Rocca di Pietracassia, Medieval fortress in Lajatico, Italy.

Rocca di Pietracassia is a ruined medieval castle at 534 meters above sea level in Lajatico, overlooking the Sterza valley. It consists of two parts: an older square castle with a keep and two towers (one square, one heptagonal) connected by thick walls, and a 13th-century outer wall of large limestone blocks. The north side ends at a rocky cliff.

The first written record of the fortress dates from 1028, when it marked the border between the diocese of Volterra and Pisan territory; some authors place its origin in the Lombard period. In 1115 the bishop Ruggieri of Volterra bought it for 50 lire. After the Pisan defeat at Meloria in 1284 it passed to Lucca and Florence, and in 1431, after a revolt, it was retaken and dismantled.

The name Pietracassia comes from a natural crack in the foundation rock, showing how the builders connected their structure to the local landscape. This geological feature shaped how people understood and used the fortress within its surroundings.

Visitors need to park at Poggio delle Cataste and walk a 2 kilometer path through oak forests to reach the fortress. Wear comfortable shoes and bring water, as the trail takes about an hour to complete on foot.

The castle's eastern tower is the only part still accessible, and it keeps its barrel vault. The main south facade has no openings or battlements; its arrow slits were added later. The entrance near the western tower is raised above ground and now badly damaged.