Boštanj (pronounced [ˈbɔːʃtan], sometimes Boštanjska vas, German: Weißenstein[2]) is a formerly independent settlement in the southern part of the village of Veliko Mlačevo in central Slovenia.

Prehistoric burial mounds and Roman graves have been discovered at Boštanj, attesting to early habitation of the area.

In 1678 ownership was assumed by the Ursini von Blagay family, who remained the owners until the beginning of the 20th century.

It was a Renaissance castle designed like a fortress with a central rectangular building fortified with towers and a defensive wall.

[6] The castle contained many late Gothic and Renaissance architectural elements, and also featured valuable Rococo and Classicist murals and ceiling paintings.