Lichnice Castle, Castle ruin in Třemošnice, Czech Republic

Lichnice Castle is a ruin located on a hillside near Třemošnice in the Iron Mountains region. The site features stone walls arranged in a triangular layout with two residential towers remaining from the medieval period.

Founded probably by King Wenceslaus I in the mid-13th century, the castle was first documented in 1261 under Smil of Lichtenburg. Hussite troops under Hynek Krušina of Lichtenburg took it in 1421, and an unsuccessful siege followed in 1428. The Trčka of Lípa family acquired it in 1490 and rebuilt it in late Gothic style; after a 1610 fire it decayed, and by 1700 it was a ruin.

The castle gave its name to the Lichtenburg family: Smil of Ronow called himself "Smil of Lichtenburg" after the castle in 1261, founding the von Lichtenburg line. The Czech name Lichnice derives from the Middle High German licht, meaning light, so the original name meant "light castle".

The ruin is reached by walking along a marked trail that climbs from Třemošnice upward toward the hilltop. The ascent is steep, but visitors are rewarded with views across the surrounding countryside.

The castle was probably founded by King Wenceslaus I around the mid-13th century, but the unfinished perimeter was beyond Smil of Lichtenburg's means, so the plan was reduced to a small bergfried-type core with a modest palace.