The Velsk Trinity Cathedral, featuring three altars, was built in the mid-18th century and later underwent several renovations in the early 19th-century classicism style. Architecturally, it was a two-light square with two apses in the altar, topped with a decorative five-domed structure, a refectory, and a three-tiered bell tower with a spire. The altars were consecrated in honor of the Holy Trinity, the icon of the Mother of God "Tolga," and the saints Athanasius the Great and John the Merciful.

Among the church relics was a handwritten Gospel, gifted in 1557 to the Nikolai Church by Vasily Parfentyev. The second cathedral church, the Transfiguration Church of Velsk, was built in 1913. Its altars are dedicated to the Transfiguration of the Lord, Archdeacon Stephen, and St. Seraphim of Sarov.

Three churches were associated with the cathedral: the Assumption Cemetery Church, built between 1795 and 1802 and still standing today; the Nikolai Cemetery Church, erected in 1908 and now lost; and the Pokrov Church, built in 1898 in the village of Ovsianikovo of the Ust-Velsk district (now the village of Pokrovskoye).

The Trinity Cathedral was closed in the 1930s and was completely destroyed by the 1950s. Today, the site is occupied by the former district committee building, which now houses the prosecutor's office, and a roadway runs through it.