The Marettimo island has a surface of 12 square km. It is the more mountainous island of the archipelago . The highest mountain (686m) is called “Falcone”. The circumnavigation of the island is about 10 miles. The harbour is placed in the southern part of the island. It offer a good shelter from northern winds. If sirocco wind blows you can shelter  in the northern part of the island ( Mezzo).

Lighthouses and lanterns: In the harbour fix red light; range 3 miles and at the end of San Simone dock a green light with a range of 3 miles. Lighthouse Faro  two white flashes each 15 seconds; range 25 miles  (height :73 m) .