Serpukhov Kremlin, Medieval fortress in Serpukhov, Russia.

Serpukhov Kremlin stands on the left bank of the Nara River on Cathedral Hill. Only its foundation and two fragments of a white-stone wall remain; the wooden building in the photograph is not part of the medieval fortress.

Construction of the fortress began in 1556 under Tsar Ivan IV as part of Russia's territorial expansion southward from Moscow. It served to protect trade routes and secure the region's southern frontier.

The name Serpukhov may derive from the Serpeyka river, which met the Nara below the hill; the wooden fort was raised on that cape in 1374. The white-stone walls were dismantled in 1934, and their stone went to build the Moscow metro. Only the foundation and two wall fragments remain, with the Cathedral Hill and its churches above the Nara.

Only the foundation and two wall fragments remain on Cathedral Hill above the Nara, so there is little to climb; the site is reached on foot from the old town. The surviving stone is uneven underfoot, and the slope can be muddy after rain.

The fortress was positioned strategically to overlook the river and repel invasions from the south. This geographic location made it a critical point for defending the Moscow region.