Burgruine Kaja

Austria, Austria

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Burgruine Kaja, often just called Ruine Kaja, is a ruined medieval hill castle in Lower Austria, situated near the village of Merkersdorf in the Waldviertel region, close to the Nationalpark Thayatal and the Thaya River on the border with the Czech Republic.

Dating back to the 12th century, it was originally a strategic stronghold for the Lords of Chiowe and later served as a border fortress and, in the 14th century, as a notorious robber‑knight castle before falling into decline.

Today its restored walls and towers stand as a well‑preserved ruin, with a visitable keep, a deep well, a dungeon, palace rooms, a chapel, and other medieval features, all set within scenic woodland that makes it a popular hiking and cultural destination with guided tours and seasonal events.