The Mozhaisk Kremlin is on the Sobornaya Gora in the center of the city. In the past it was a strong citadel defending the southern borders of Moscow principality. In 12 century the citadel was encircled by wooden walls. In 1624 they were replaced by the walls of white stone.

In 1303 Mozhaisk was included in Moscow principality, and the town, which was then within this small citadel and a posad (trading quarter) around it, began to actively develop. In those years Mozhaisk acquired not only military but also religious significance thanks to the cult of St. Nicholas of Mozhaisk.

The earth banks, with wooden and then stone walls, remained to our days. One can clearly see the sites of 6 strong towers of the kremlin. Of the city wall of 1624 there remained only the Petrovskie Gates, which were the main entrance to the kremlin.

There remained only two buildings on the territory of the kremlin. They are the Cathedral of St. Nicholas and the Cathedral of Peter and Paul. The Cathedral of St. Nicholas was built in 1779. It has the characteristic features of the European medieval Gothic style. The nearby Cathedral of Peter and Paul was built in 14 century. However, of it there remained nothing but the foundation and some fragments. As a whole the cathedral was completely rebuilt in 1849.

If you go down from the Cathedral of Peter and Paul to the foot of the hill, you can see there a spring lake, which was mentioned even in the ancient chronicles, and near it a monument devoted to World War II.