Among the most historical monuments and places of historical interest are Panagia Gremiotissa, the tomb of Homer, and the prehistoric settlement of Skarkos. The churches of the island have been designated preserved, historical monuments of the post-Byzantine years mainly. Apart from Panagia Gremiotissa, most churches are located in Chora and the port, while small churches can be found in areas such as Kalamos, Psathi, and Paleokastro. A local tradition wishes there were 365 churches on the island, one for each day of the year. Panagia Gremiotissa is the most famous church of Ios, which was built in the 18th century on top of the hill of Chora, next to the Venetian walls, and is dedicated to Panagia. The tomb of the glorious poet Homer is located in the area of ​​Plakotos on the island’s north side, on the hill of Psathopyrgos. Many sources state that the poet died on Ios after he failed to solve a riddle set for him by the fishermen of the island. The prehistoric settlement of Skarkos is located in the area of ​​Kampos and has an area of ​​eleven acres. It is the largest to date settlement of Proto-Cycladic civilization during its full bloom, the Early Bronze Age. The findings are exhibited at the Archaeological Museum of the island. The settlement of Skarkos has been awarded for the good preservation and promotion of antiquities at an international level.