Kos (Town)
The Asclepieion of Kos is built upon the slopes of hill clothed in lush flora and graced with beautiful views of the sea and the Turkish coast. It is the most important monument of the island and of the most important temples of its kind of antiquity. In the ancient times it was the place of worship of the god Asclepius, healing grounds for the ill and a school for the study of medicine. Hippocrates, one of the greatest exemplars of the medical profession taught in the school that he instituted within the sanctuary`s area. In contrast to the more arcane sanctum of Asclepius in Epidaurus, its counterpart in Kos Island cultivated scientific medicine.

The Asclepieion of Kos, whose surviving ruins are dated to the 4th century B.C, is located 2 miles northwest of the city. The three successive terraces are dated to the Hellenistic years; their specific oriental style was probably adopted after Alexander`s conquests. During the reign of the Ptolemys` in 260 BC a critical event marked the history of the monument. The Asclepieion was recognized as a Pan-Hellenic asylum for the preparation of the celebration of the Asclepieia. The pursuit of the islanders to offer asylum to those prosecuted, is a clear sign of how proud they were for their temple which they considered to be the center of their city.

Kos (Town)
The Roman Auditorium is thought to have been one of the most crucial public buildings of ancient Kos. Erected during the 2nd century AD it is believed to have taken the place of an older public building that could have been the parliament of the city. Despite the auditorium being originally designed for hosting musical competitions, it was also used as the seat for the local senate. The building was initially roofed and seated approximately 750 persons. Its cavea with a northern orientation was supported by arched constructions built on pillars of caster masonry (opus caementicium). It had fourteen rows of marble seats, nineteen of which have been restored, and was divided by a corridor into two sections; the cunei of the lower section were divided by four staircases. Under the cavea lied two semicircular porticos and a series of rooms used as shops or workrooms. The form of the scene was unusual: an irregular pentagon made of two parts, the proscenium (front of scene) and the paraskenio (backstage), communicating thanks to three entrances. On both sides of the scene were two more doors leading to the parodoi (passageways). The floor of the circular orchestra was decorated with opus sectile (marble works), while mosaic floorings adorned the parodoi.

The inner galleries of the Odeon were decorated with marble statues initially standing in niches; the most notable is that of Hippocrates, today exhibited at the Archaeological Museum of Kos. Today the auditorium hosts a number of cultural happenings. Moreover, within the Auditorium the exhibition of photography of the Aegean Institute of archeological studies is housed.

Kos (Town)
The Casa Romana is one of the most interesting sites on the island of Kos. In 1933 the great earthquake nearly destroyed the whole island. The Italians, who at the time of the earthquake were occupying the island, perceived the destruction as an opportunity to reconstruct the city`s building plan, conducting numerous excavations, with the knowledge that beneath the leveled structures ancient monuments lay.

The site is a Roman Manor of the Pompeii model, erected between the late 2nd and the early 3rd century AD. Built on the ruins of an earlier Hellenistic house, with an excellent drainage system, the manor comprises 36 rooms and three atriums. Its exterior view of the site does not prepare the visitor for what lies within. Walking through the main entrance one only begins to grasp the manor`s beauty. There one encounters a statue`s base bearing the inscription `ΑΠΕΛΕΞΙΚΑΚΟΣ` (he who repels evil). In the first atrium a small reservoir and a mosaic portraying a panther devouring a deer, of pristine quality, may be found. Nearly every room of the manor features stunning mosaics and beautiful decors. The manor`s central room (`ανδρώνας`) exhibits signs of orthomarmarosis and bear mosaic floors of geometric ornaments, depictions of tigers, panthers and others. The auxiliary rooms are to be found in the northwest side near the stairs leading to the first floor. In every atrium one may find reservoirs of various sizes and mosaics of mythological and physical subjects such as the Niriyds or dolphins. Within the structure, statues of nymphs, of Athena and a mosaic depicting the ocean bed can be viewed.

Kos (Town)
The church of Saint John the Baptist is an early Christian Baptistery built in the 5th or 6th century AD. The temple is located inside the cemetery of the city and today it functions as the cemetery church of the city of Kos. It is perhaps the only early Christian Baptistery surviving to this day. The building was surrounded by wide, vaulted corridors, from which only the foundations remain today. On the outside it is shaped as a rectangle, while on the inside it has a circular shape, with four alcoves in its four corners and one in the middle of its eastern side. However its walls form 8 dents, together with one to the west, 7 of which resemble altars (Bemas) of the eastern orthodox churches. This is why the temple is known as the `Seven Bemas` church. Recently in the temple frescoes dated to the 12th or 13th century have been uncovered, portraying scenes from the life of the Saint.

Antimachia
The castle of Antimachia is located in the center of the island of Kos, southeast of the village of Antimachia. It is a remarkable medieval fortress. According to written testaments of the 14th century, the castle also served as a prison for condemned knights.The castle is built along a hill with a view to the southern coast of Kos. It has a triangular shape with a peak to the east. Every side of the castle is organized as an independent fortification line that follows the shape of the terrain. At the entrance there is a massive crescent shaped bastion with deep ramparts. The castle was renovated by the Knights Templar in 1494 after a destructive earthquake. The existing walls were reinforced and new battlements of various types were added along the external wall. Inside the castle, one still finds ruins of the old settlement of Antimachia, many cisterns and two churches. The settlement was abandoned in 1840.

Pyli
The ruins of the old town of Pyli and its castle can be found on a hilltop, 3 miles away from the modern village of Pyli, approximately 10 miles from the city of Kos. The old town is an abandoned settlement on the foot of a Byzantine castle, built in the times of Macedonian dynasty (9th-11th century AD). When the knights of Saint John took hold of the island in the 14th century, they enforced the fortifications on the castle in order to improve the area`s defensive capacities. From the castle the visitor will enjoy magnificent views of the nearby islands of Pserimos and Kalymnos and of the shores of Asia Minor.

The old town itself has been called `the Mystras of the Dodekanese`, implying the importance of its medieval archaeological monuments such as its byzantine churches. Of particular importance is the 14th century church of Ypapanti (Candlemas), with its beautiful frescoes, a wonderful wood carved altar piece and columns from an older temple of the vicinity. Another church worth visiting is the temple of the Archangels (church of the Taxiarche). It should also be noted that that the founder of the monastery of Patmos saint Christodoulos originally founded a monastery here in Pyli, the monastery of the Castriani, the Catholicon of which is still preserved today as the Flevariotisa church.

Dated between 140-100 million years ago the cave of aspri petra can be found atop mount Zini in Kefalos, at an altitude of 850 feet, in the southwestern part of the island. The cave is composed of layers of solid and dry rock which enabled its continuous use, initially as a place of residence and later as a place of worship. Human fossils and multiple ceramic urns of bowlike-sagittal handles decorated with varying figures and of various sizes were prominent among the findings, with weaponry being very rare. Few blades and sharp cores made of obsidian, from Yali, an Island near Nisiros. The remnants of the nutriments speak of a people dedicated to pastoral life. Of note was the presence of holes filled with egg shaped milestones. The cave is one of the oldest monuments of the island.

Kos (Town)
Located near the Plane Tree of Hippocrates, this temple, dedicated to Hercules, is dated from the 2nd century BC. It is built upon a trapezoid shaped mound. The temple is considered to have been dedicated to Hercules, due to an inscription and objects associated with Hercules found on the site as well as findings related to the legend of this hero. According to historical sources after the demolition of the surrounding area between the second and third centuries A.D, a colonnade was erected and decorated with mosaics. One of these mosaics depicted the `Symposium of Hercules.` In the same area one may encounter buildings belonging to later eras, such as a baptistery and a small bathhouse.

Kos (Town)
In antiquity, the agora (forum) of every city was its commercial and social center. The ancient Agora of Kos is among the largest to have been excavated in Greece to this date. Originally it was built during the 4th century BC near the city`s port. After 366 BC when the city of Kos was recognized as an important administrative center, important public and religious buildings were constructed in the area of the port and of the Agora. The latter was the financial heart of the island, with streets, workshops, shops and altars that constitute the `traditional` image of an ancient agora. The Agora had three main gates (eastern, western, and northern). The roads from the three gates converged in the center in a large internal courtyard. The northern gate connected the Agora with the city walls, while the other two hosted a number of shops tending to the citizens` everyday needs.

The frequent earthquakes hitting the island were a reason for repeated reconstructions of the city. Different materials used by the locals help distinguish the different construction phases. The earthquake of the 6th or 5th century BC left no traces to the construction history of the city. From 366 BC and all through the third century, buildings are created with `amygdalopetra`, a type of limestone and greenish porous stone. Marble is rare. During the next period, marble is used widely. During the 2nd century BC the monumental buildings are constructed, giving a magnificent view to the city. The reconstruction that followed the earthquake of 142 A.D. changed the image of the city once again. New construction methods were used (cast wall making) and new buildings and complexes are constructed, such as the Thermes, the theater and the stadium. The agora and the neighboring building blocks were reconstructed.

The earthquake of 469 A.D. brought a critical change that marked the end of the ancient city and the beginning of the early Christian era. Today, the ruins of the Agora are part of the broader archaeological zone of the port, which covers an area of 500 feet long by 270 feet wide. The visitor can see among others the Agora, part of the fortification of the city, the sanctuaries of Aphrodite and Hercules, building blocks with some remains of private houses but also a part of the ancient port of the city. However the biggest part of the Agora lays buried under the modern city. The southern part of the Agora was only recently excavated, opposite the altar of Dionysus.

Pyli
The ancient tomb of King Harmylos, ruler of the island, is one of the most curious and interesting archeological monuments of Kos. Located in the neighborhood Harmyli of the village Pyli, aptly named after the monument, the site is located 300 yards away from the main square. It consists of a semicircular building containing 12 crypts ordered in parallel lines of 6, built within the walls. The tomb is dated approximately to the 3rd century BC. It served as an heroon (temple dedicated to a hero) in its time. In olden times the façade of the building was covered by an ionic gallery chiseled in white marble. The said marble tiles along with the inscription which confesses to the date of the monument were removed from their original places and can now be found mounted onto the walls of the church of Stavros, above the tomb itself.

Kos (Town)
The castle of Kos, better known as the castle of Nerantzia (castle of the sour orange tree), is the most important part of the fortifications constructed on the island by the Knights Templar at the end of the 14th century A.D. It owes its name to the many sour orange trees that were planted in Kos during the late years of the 14th century and the early years of the 15th century, when the whole city came to be called by this name.

The castle consists of two fortified curtain walls. The inner curtain wall is the oldest. It is rectangular shaped and on its corners boasts 4 high towers. A wide moat (ditch) separates the two curtain walls which are connected only by a single inclined road on the eastern side of the castle. The castle of Nerantzia along with the castle of Saint Peter on the opposite coast of Ancient Alicarnasus (today`s Bodrum Castle) controlled the sea way towards the holly lands during the period of the crusades. In the construction of the castle various architectural elements from the ancient city of Kos and the Asclepieion were used. Many of these can still be seen today embedded in the walls of the castle. During the 19th century the castle was used as the barracks of the Turkish garrisson and as the home of the Turkish commander of the island. During the German occupation, the castle hosted the German garrison and was used as a prison for the imprisonment of Greek patriots.

Kos (town)
In the center of Kos island in front of the Castle of Knights stands a huge old plane tree, known as the Hippocrates plane tree. It is claimed that Hippocrates used to sit under this plane tree and teach his students. As the tree is 500 years old, it is obviously not the one that Hippocrates planted, since he lived around the 5th century BC. This plane tree has a perimeter of 40 feet, which gave it the reputation of being the largest in Europe. The island`s authorities have taken some measures in order to preserve it. A short surrounding wall with a metal railing prevents it from extending excessively and keeps people in proper distance. The wall has Turkish ornaments on one side of this wall, while on the other there is a historic white engraved tap in Arabic language, put by a Turkish governor. The tree has made history around the world, since some of its cuttings or seeds went to several destinations as gifts. For example, to the grounds surrounding the National Library of Medicine in the United States, where its seeds were planted in 1961. The Department of Medical Genetics at the University of Glasgow, the Michigan Medical School, and the Sydney`s School of Rural Health in Australia are just a few examples of the many institutions that hold derivations of the Hippocrates plane tree.