Burg Krosigk, Medieval castle in Petersberg, Germany.

Burg Krosigk is a castle in Petersberg featuring a tower dating back to the 12th century and segments of its original protective wall. A wide moat encircles the fortress to defend the enclosed space.

The fortress was originally built as a ministerial castle and served as a defensive stronghold during medieval times in the Saxony-Anhalt region. It held importance for controlling and securing the surrounding territory.

The name Krosigk comes from the Frankish noble family that held the castle; Dedo von Krosigk appears as a witness in a 1103 charter of Bishop Walram of Naumburg. In 1115 Wiprecht von Groitzsch the Younger, leader of the Saxon noble opposition to Emperor Henry V, found refuge on Dedo's lands. The site is now owned by the municipality and freely accessible; the tower opens during the village festival and on the third Saturday of each month from April to September.

The grounds are open to explore and connect to walking paths toward the nearby Krosigk windmill and water mill. Sturdy footwear is recommended since the terrain can be uneven.

The castle was destroyed by Swedish troops on 23 October 1644; the date of any rebuilding is unknown. In 1701 Wolf Friedrich von Trotha built the manor house on the outer bailey site, and in 1703 the chapel. The von Trotha family owned the estate until 1813, when debts forced its sale.