Holy Trinity monastery, Alatyr, Orthodox monastery in Alatyr, Russia.

The Holy Trinity Monastery in Alatyr comprises the two-storey Trinity Cathedral, the Sergius Church with a Kazan Icon chapel, a cave church, and stone residential and service buildings from the 18th–19th centuries. Its bell tower, 81.6 metres to the cross, is finished in pink brick with white marble details and a copper tent crowned by a gold cupola.

Founded around 1584 during the late 16th century, this monastery has witnessed over four centuries of Russian history, surviving periods of imperial rule, Soviet restrictions, and post-Soviet restoration.

The monastery's name comes from its main cathedral, dedicated to the Holy Trinity. The Kazan Icon of the Mother of God is venerated in a side chapel built in 1848 over the grave of schema-monk Vassian, whose incorrupt relics were honoured there from 1748 until the early 1930s. The cave church, restored in 1997, recalls the 1905 crypt.

The monastery stands on the northern side of Alatyr, so approach from the town centre heading north. The bell tower, 81.6 m to the base of its cross, serves as the main gate into the grounds, and its spire and ringing can be seen and heard from almost anywhere in the city. The buildings are stone structures of the 18th–19th centuries; the cave church is the one structure that survived the 1906 fire.

The bell tower reaches 81.6 metres to the base of its cross, so its spire is visible and its bells audible from almost anywhere in Alatyr. Its pink brick walls are trimmed with white marble, and the copper tent roof has gilded ribs. It also serves as the monastery's main gate, which is why it is called a gate tower.