Kostomlaty is a striking ruined castle perched on a hilltop above the village of Kostomlaty pod Milešovkou, offering hikers a fascinating glimpse into medieval Bohemia. Built in the first half of the 14th century as a bergfried-type castle, it witnessed Hussite sieges, noble feuds, and centuries of slow decay before becoming a protected cultural monument.

The climb rewards you with atmospheric ruins scattered across a forested hilltop in the heart of the České středohoří region — a massive keep, remnants of two palaces, and traces of ancient gates and ramparts. From the restored tower you'll enjoy sweeping views over the Krušné hory (Ore Mountains) and the České středohoří hills, with Teplice and Doubravská hora visible on clear days. In spring and summer the surrounding woods are lush and green, autumn brings misty, moody vistas perfect for photography, and winter transforms the ruins into a quiet, frost-dusted spectacle.

• From the village of Kostomlaty — green trail marker, approx. 1,500 m, 150 m elevation gain, moderate difficulty
• Alternative, easier approach — join the same green trail where it crosses the Kostomlaty–Milešov road

• Summit elevation: 566 m above sea level
• The main tower was restored in 2014 and now houses a lookout point
• Protected as a cultural monument since 1964
• Maintained by a local civic association dedicated to the castle's preservation

Fun fact: the castle was once mistakenly called 'Sukoslav', based on a fabricated legend by chronicler Václav Hájek z Libočan — a name with no real historical basis. In 2007 the ruins served as a filming location for Zdeněk Troška's fairy-tale film 'Nejkrásnější hádanka'.