Alexandrov Kremlin, Medieval fortress in Alexandrov, Russia.

The Alexandrov Kremlin is a fortified complex in Alexandrov featuring stone churches, defensive walls, and towers spread across several hectares of ground. The site includes multiple structures that together present the layout and scale of this significant medieval Russian fortress.

Known since the 14th century, the settlement became a country residence of Grand Duke Vasily III, whose palace was built by 1513 and whose Intercession Cathedral was consecrated that year. Ivan the Terrible made it his residence from 1565 to 1581, when it served as the de facto capital of the state and the centre of the oprichnina; he left after the death of his son Ivan and never returned. In the second half of the 17th century an Assumption nunnery was established on the former fortress grounds.

The Trinity Cathedral keeps 16th-century frescoes and white-stone carvings on its inner portals. Its south entrance holds the Vasilyevsky Gates taken from Novgorod's St Sophia Cathedral in 1336, showing religious scenes beside a centaur; the west entrance has 1344–1358 doors from Tver's Transfiguration Cathedral, one plate etched with the Trinity.

The fortress is open to visitors daily, and guided tours in multiple languages can be arranged by advance request. Wear sturdy shoes since the ground is uneven and pathways connect various buildings and walls throughout the site.

The two sets of 14th-century doors in the Trinity Cathedral are not copper: the Vasilyevsky Gates (1336) from Novgorod's St Sophia Cathedral were gilded by rubbing liquid gold and mercury into carved recesses, and the Tver doors (1344–1358) from the Transfiguration Cathedral still carry an etched Trinity on one plate. Ivan the Terrible installed them at the south and west entrances.