The Dormition Cathedral is the oldest building in Klin but its exact date of foundation is unknown, though believed to date from the mid-16th century. One legend states that it was built on the orders of Tsar Ivan the Terrible to repent for ravaging the city during the Oprichnina period. Previously it was the main cathedral of a monastery which was closed in 1764. The cathedral was heavily reconstructed in the 19th century in the classical style. Opposite the cathedral is a small belfry.