The ancient city of Chersonasus has not exactly vanished — it is right there at the eastern end of the modern harbour, in scattered open patches that the resort grew around rather than over. The Roman pyramidal fountain on the seafront, with its surviving mosaics of fish and fishermen, is the centrepiece and is freely accessible. Above it on the headland are the foundations of two early Christian basilicas with surviving floor mosaics — Basilica A is the more complete — and several rock-cut tombs of the necropolis cut into the cliff.
It is not a major site by Cretan standards (Knossos is half an hour away) and the explanatory signage is patchy, but a half-hour walk between the harbour fountain and the basilicas gives a useful sense of how old the place is beneath the tourist veneer. Visit early morning before the sun is high — there is no shade and almost no entry fee.