Tepenec Castle (German: Burg Twingenberg, aka Karlsburg) is a former castle in the vicinity of Jívová in Moravia, Czech Republic. The castle was built by Emperor Charles IV between 1340 and 1346. It stood in the Bělkovic valley, 4 kilometres (2.5 mi) east of Sternberg in Moravia. Charles named it Twingenberg after an eponymous castle in Luxembourg. The castle was destroyed in 1391.