Bodrum castle, also known as the Castle of St. Peter, is a medieval fortress located in the coastal town of Bodrum in Turkey. It was built by the Knights Hospitaller of St. John, a Catholic military order, in the 15th century. The castle is named after St. Peter, who is the patron saint of the order.

The castle is one of the best-preserved examples of medieval architecture in Turkey. It is built on a peninsula that juts out into the Aegean Sea, providing a strategic location for defense. The castle's walls, towers, and ramparts are made of stone and are fortified with battlements and loopholes. There are also four circular towers that served as lookout points for the knights.

Inside the castle, there are several exhibits that showcase the history of the region, including artifacts from the ancient city of Halicarnassus and the Ottoman Empire. The castle also houses the Museum of Underwater Archaeology, which displays ancient shipwrecks and artifacts recovered from the sea.

Bodrum castle is also known for its impressive architecture, particularly the gothic arches and the impressive gatehouse. Visitors can also explore the dungeons and the medieval chapel inside the castle walls.

Today, Bodrum castle is a popular tourist attraction, drawing visitors from all over the world to explore its history, architecture, and exhibits. It was recognized as a UNESCO World Heritage site in 1994.