One of the unique attractions of Gatchina is the Priory Castle, which, although less known in Russia compared to other architectural monuments of the pre-revolutionary era, deserves more attention due to its unusual construction technology and other interesting elements. The castle, also known as the Priory Palace, was founded in 1797. Its project was developed by the outstanding Russian architect Nikolai Alexandrovich Lvov, known for his bold construction experiments and significant contributions to architecture.

The history of this castle's creation is linked to the reign of Emperor Paul I, who provided refuge to the Knights of the Maltese Order. The knights needed a worthy residence, and the emperor handed over his palace to them, while commissioning Lvov to build a new one for himself. Paul I, possessing a rich imagination and unafraid of innovations, enthusiastically accepted the proposal to erect the castle using new technology. He personally oversaw the construction and at that time was already effectively leading the Maltese Order, so the appearance of the unusual palace coincided with his new powers. The palace was built in just a few months, and its rammed earth walls became a rarity, being the only ones in Russia.

The uniqueness of Lvov's method lay in the use of loose sedimentary rock mixed with lime mortar, which created a durable material. Several other buildings were constructed in Russia using this technology, but they have not survived. As for the use of the palace, Paul I visited it rarely, and his heir Alexander visited it only once. After Paul's death, the castle passed into the state treasury. Nicholas I and heir Alexander Nikolaevich visited it, and it was here that Alexander met his future wife, but no one from the dynasty lived in the castle afterward. During World War I, the palace was used as a hospital, and in the Soviet era, it was abandoned and fell into ruin until it reopened to visitors in 2004.