Mydlovar Castle, Gothic castle ruin in Šnepov, Czech Republic.

Mydlovar Castle is a ruined medieval castle on an artificially raised hill on the right bank of the Elbe, 2.5 km southeast of Ostrá. Its main defence was a brick mantle wall, parts of which still rise above the ground; the perimeter wall and buildings collapsed into the courtyard, raising the terrain above its medieval level. It is probably the only castle in Bohemia built mainly of brick.

The castle was built in the second half of the 13th century, first mentioned by name in 1356. In 1402 it was acquired by Jan Puška of Kunštát, and after 1425 it passed to the Poděbrady family. Confiscated in 1547 from Bedřich z Donína, it was annexed to Lysá and first recorded as deserted in 1561.

The castle holds official status as a cultural monument of the Czech Republic, reflecting the architectural developments of medieval Bohemian nobility.

The ruins are reached by marked paths and sit in open terrain with no physical barriers to access. Wear good walking shoes since the ground is uneven and rough.

Local legend credits Princess Libuše with founding the castle as a summer residence and with planting the snowdrop-like Scilla in her garden, from where it spread into Mydlovarský luh. A wooden footbridge over the Elbe was said to let her attend church in Hradištko.