Georgenburg Castle, Medieval castle in Mayovka, Russia

Georgenburg Castle is a medieval castle ruin in the village of Mayovka, near Chernyakhovsk in the Kaliningrad region of Russia, set on a rise above the Instruch River. Stone wall sections and partial foundations survive across the site, giving a clear sense of the original footprint of the fortification.

The first fortification was built in 1264 by the Teutonic knight Hartmann von Grumbach on the site of the Prussian hillfort Kapzowin and named after Saint George. The castle was rebuilt in stone in 1351 and again between 1385 and 1390, after Lithuanian raids destroyed it in 1364 and 1376. From 1709 it was a state domain, and under the tenants von Keudel horse breeding began there.

The name Georgenburg comes from Saint George, the patron saint held in high regard by the Teutonic Order. Visitors walking through the site today can still read the layout of the old fortification in the surviving stonework.

The site is reached on foot along a trail north of Chernyakhovsk that follows the Instruch River, and sturdy footwear is a good idea given the uneven and overgrown ground. Visiting in dry weather makes it much easier to move around and take in the layout of the ruins.

The stud farm beside the castle traces its origins to the estate's own horse breeding under the von Keudel leaseholders from 1709, and it was the Scottish breeder William Simpson who later made it famous and contributed to the Trakehner breed. In 1899 the state bought Georgenburg back and made it the main state stud of Prussia, joining the Insterburg stud under its management in 1929.