Ancient Lissos was the seaport of Elyros and was built in a small valley between ancient Syia (current Sougia) and Paleochora. It flourished from the Hellenistic period up to the 9th century, when it was destroyed by the Saracens. It was famous for the Asclepion, where patients from all over the island arrived to be healed from the thermal baths.
You can still see the mosaic floors of the temple of Asclepius with depictions of animals, which was destroyed by an earthquake. A walk in the valley of Lissos will impress you, as the area is dispersed with ancient ruins, such as pillars, building bases and pieces of marble.
You will see the Roman necropolis with vaulted tombs and ruins of the Roman theater. The area hosted dozens of statues and coins of Lissos, indicating that Lissos was one of the most powerful towns in Crete. The most important statues were these of Goddess of Health (Hygeia), Asclepius and Pluto, that can be seen at the Archaeological Museum of Chania.
Near the sea there is the church of Saint Kirikos that was built on the site of an early Christian church (4th-5th century AD) and there are architectural parts embeded in its walls. It celebrates on July 15, when dozens of pilgrims arrive at Lissos and stay overnight (the previous night) to participate at the fest. Some meters to the north there is the church of Panagia. Lissos can be accessed either by the E4 path from Paleochora or through the gorge of Lissos, which starts from Sougia, or by boat from Sougia or Paleochora that leaves you on the beautiful beach of Agios Kirkos, but also through a dirt road from Prodromi.