Khotyn fortress, also known as Hotin Fortress, is a medieval castle located in the city of Khotyn in western Ukraine. It is situated on a high bank of the Dniester River and is considered one of the most important fortifications of medieval Europe. The fortress was built in the 13th century and has been used as a military fortification, a residence of noble families, and a prison throughout its history.

Khotyn fortress was the site of several significant battles, including the Battle of Khotyn in 1621 between the Ottoman Empire and the Polish-Lithuanian Commonwealth. The fortress was badly damaged in the battle, but was later rebuilt and improved upon by the Ottoman Empire, who added a large gate tower and a mosque to the fortress.

Today, the Khotyn fortress is a popular tourist attraction, offering breathtaking views of the surrounding landscape and a glimpse into the history of medieval Europe. Visitors can explore the castle walls, the remains of the mosque and the gate tower, and the several exhibitions showcasing the history and architecture of the fortress.