The Monastery of Panormitis is the main religious center on the island. It is dedicated to Archangel Michael and celebrated on November 8th. This male monastery receives many pilgrims every summer.
The Venetian Castle of Simi was built by the Knights of Saint John on the site of a Byzantine Castle. It stands on a hill above the Town and gives great views to the harbor.
The Nautical Museum is located in Gialos. It hosts ship models, old maps and compasses, maritime instruments, old diving uniforms and many other items that depict the long nautical history of the island.
The Monastery of Roukouniotis looks like a fortress and dates from the 15th century. Outside the monastery, there is a cypress in form of an umbrella.
The Archaeological Museum of Simi is housed in an elegant Venetian mansion in the Town. The archaeological collection includes Hellenistic sculpture, ancient coins, grave offerings, and small statues.
Many wine presses have been found on the island of Simi, mainly dating from the Byzantine era. Actually, there are more than 120 presses recently discovered (in 1992) by Sarantis Kritikos, scattered all over Simi.