Epidaurus is 20 miles (32 km) east of Nafplio, and about 40 miles (62 km) due southwest from Athens. Although it is now best-known for the perfect acoustics of its famous 15,000-seat theater, the theater is there because of the Sanctuary of Asclepius, which was Greece's most famous healing center during antiquity, dating from at least 600 BC. About two hundred years later the theatre was built, where music contests and plays were held. The theatre is a testament to the large number of visitors who would come to Epidaurus for healing at the same time. A number of other buildings were constructed to house the pilgrims.

The location is said to be Asclepius' birth place. Although Homer says that he was a mortal, later myth made Asclepius into the son of Apollo, the sun god. The legend is that Asclepius was the child of Apollo and the daughter of the king of Orchomenes.

The locale is named after Epidaurus, who, Homer says, was a local ruler who took part in the Trojan war. Under his charge were two generals, Podaliro and Machaon, sons of Asclepius. In the 6th century a cult dedicated to Apollo was established there. Excavations have uncovered a sanctuary from hundreds of years before that, during the Mycenaean era.

Pilgrims seeking healing would converge here from all over Greece, leaving a gift for the gods of healing, Apollo, Asclepius, and Hygeia ("hygeia" is still the Greek word for "health."). The gift was usually a clay model of the body part that needed attention. The museum there displays hundreds of these clay body parts. Then the visitor would sleep in one of the rooms of the katagogeion (patients' dormitory), and hope for a visit from one of the gods.

Epidaurus' is sited in a small valley surrounded by higher hills. Overlooking the entire complex, at an elevation of 1400 feet (430m) was the sanctuary of Apollo Maleatas. About 200 feet (70m) lower is the theater, which is a masterpiece of Greek amphitheatre architecture designed by Polycletes the Younger of Argos. Not much lower than the theatre was the Sanctuary of Asclepius and a number of other buildings including a gymnasium, baths, a stadium and the katagogeion.

By the 5th century games were being held there every four years, which is when the stadium was built.  Epidaurus reached its peak during the 4th century. The site was pillaged by the Roman general Sulla in 87 BC, but it still operated as a healing center. The famous Greek travel writer Pausanias writes about Epidaurus around 150 AD.

Epidaurus, when large numbers of tourists are absent, is a quiet place, with the feeling of being somewhat in the middle of nowhere, despite being not more than a couple days' journey from Athens.  

Epidaurus is a UNESCO World Heritage site.