The ancient city was surrounded by walls encompassing a much greater area than that delineated by the existing medieval walls. Ruins of ancient walls are still visible throughout the Old Town.
A couple of kilometres from the city centre, on the Saint Stefanos Hill (also known as Monte Smith) are the sparse remains of the Hellenistic Era of Rhodes. The site contains the ruins of a temple to Apollo, a magnificent stadium and a restored theatre.
The Acropolis dating from the Hellenistic period (3rd to 2nd century BC), is close to the town centre in an area known locally as Monte Smith (named after the English admiral William Sidney Smith who apparently kept watch on Napoleon’s Egyptian escapades from the hill top.)
The acropolis, which dominated the western and highest part of the city was not fortified like most ancient fortresses, built instead over different levels and stepped terraces.
Excavations were carried out by the Italian Archaeological School during the Italian occupation of the island from 1912-1945. As the whole of the Acropolis has not yet been excavated there is an archaeological zone of 12,500 m² that excludes contemporary building in this area.
The most important monuments in the archaeological zone are the:
- Temple of Athena Polias and Zeus Polieus on the northern edge of the Acropolis, parts of columns and bases remain.
- Nymphaia, to the east and south of the temple, four subterranean cave-like constructions cut into the rock with entrance steps, communicating passages and a large opening in the central part of the roof. They were places for recreation and worship.
- Theatre – Northwest of the impressive Stadium is a small restored marble theatre, seating for up to 800 spectators. Three seats in the front rows are original.
- Temple of Pythian Apollo – on the southern part of the hill, on the west side of a large rectangular terrace, this temple was smaller than that of Athena and Zeus but its partially restored four columns are impressive nevertheless.
- Stoa building – the foundation wall of a Stoa (arcade) is preserved, its imposing facade would have been visible from the lower town and harbour.
Artemision – on the north east side of the same terrace are ruins of this temple attributed to the cult of Artemis.
- Stadium – The Stadium, excavated and restored by the Italians is one stadion (210m) in length. The sphendone (rounded end with turning post), proedries (seats of officials) and some of the lower seats in the auditorium are original. A huge festival held by the ancient Rhodians in honour of the sun god Helios, took place here and the stadium is still used for local athletic and theatrical productions. To the east of the stadium one side of the large square gymnasium, which measured some 200m on each side was uncovered and an inscription indicates that there was a library nearby.