Among the many ensembles of Veliky Ustyug, special attention deserves the central cathedral complex, which has shaped the architectural appearance of the city from ancient times to the present day. This complex, located at the site of the original urban core, the detinets, is the oldest ensemble of Ustyug. Its emergence is closely linked to the founding of the city itself and dates back to the mid-12th century. At that time, the Ustyug detinets represented a typical ancient Russian fortress, serving as both the main architectural and artistic center of the city.

One of the first historians to study the initial development of Ustyug was V. P. Shlyapin. In his work "The Life of the Righteous Procopius, the Ustyug Miracle Worker, and the Historical Description of the Ustyug Procopius Cathedral," published in 1903, he suggested that the ancient center of Veliky Ustyug was indeed the Cathedral Square, not the Gorodishche. However, in 1915, a book by B. I. Dunaev titled "The City of Veliky Ustyug," reissued in 1919, influenced V. P. Shlyapin to change his viewpoint, agreeing that the city began with the Gorodishche. Detailed justifications for V. P. Shlyapin's original version that the core of Veliky Ustyug is the Assumption Cathedral and the cathedral square can be found in V. P. Shilnikovskaya's book "Veliky Ustyug," published in 1973 and reissued in 1987.