Brandenburg Castle, Gothic castle ruins in Ushakovo, Russia.

Brandenburg Castle is a ruined medieval stone fortress in Ushakovo, in the Kaliningrad Oblast of Russia. The complex was built around a central courtyard with four wings, and the remaining walls still show Gothic stonework typical of the Teutonic Order's building tradition.

The fortress was founded in 1266 by the Teutonic Knights as a military base during their campaigns in the eastern Baltic region. After the order lost its power, the castle gradually fell into disuse and was never rebuilt on a large scale.

The village where the castle stands was once called Brandenburg in German, and the fortress took its name from that settlement. Visitors who walk around the outer walls can still read traces of that Central European past in the stonework.

Parts of the ruins can be walked through, but the ground is uneven and gets slippery after rain, so sturdy shoes are a good idea. Some sections may be temporarily closed, so it is worth checking the current state of access before making the trip.

A limestone well in the northeast section of the complex remained in use until 1838, long after the fortress had lost its military role. It supplied the entire site with water, which tells a lot about how the space continued to function as a living place well past its years as a stronghold.