Castello di Medusa, Medieval castle ruins on granite hill in Lotzorai, Italy.

Castello di Medusa is a ruined castle on a hill between Lotzorai and Girasole, near the mouth of the Rio Girasole. Only some ruins remain, covered by vegetation but easily accessible: the circuit of walls, the east facade and a room with an arched ceiling and white plaster, though in poor condition.

The castle's first construction date is unknown, as no systematic archaeological excavations have been carried out. In 1841 Vittorio Angius recorded a local tradition that it was built by a queen Medusa, and reported that it stood on the ruins of a Punic-Roman temple. The first documented mention dates to 1305, when it appears as castrum de Ollastro among the holdings of judge Giovanna Visconti. A letter of 2 March 1308 reports that Pisa was destroying castles including that of Ogliastra ahead of an Aragonese invasion; it was later governed by a castellan until 1323.

Local tradition, recorded by Vittorio Angius in 1841, says the castle was built by a queen named Medusa, whose features are lost in myth. Another tale tells of a Spanish princess from Navarre who stayed here, and of an underground passage running under the village to the river for escape in times of danger.

Access to the ruins is via a marked path starting from Via Roma in Lotzorai, and the hike requires a steady pace with sturdy footwear recommended. The trail has steep and rocky sections, so arriving with adequate time and water is important for a comfortable visit.

Local tradition, recorded by Vittorio Angius in 1841, holds that the castle was built by a queen named Medusa, whose features are lost in myth. Another tale tells of a Spanish princess from Navarre who stayed here, and of an underground passage running through the village to the river for escape in danger.