Before the reign of Emperor Nicholas I, the territory of the future Alexandria Park was occupied by the Yegerskaya Sloboda, which by his decree was relocated to Old Peterhof, and palace-park construction immediately began on the freed-up land. Near the Cottage Palace, an entire royal dacha settlement formed, with numerous residential and service buildings. Elements of neo-Gothic architecture were used in their design. At the entrance to Alexandria stood an octagonal guardhouse building, built by Menelas as early as 1827. In 1834, Charlemagne partially altered it by adding a second floor. In the second half of the 19th century, the buildings on the right side of the road were converted into dachas. In the former "Cavalier House," the dacha was rented by Rear Admiral Posyet, and the Obolensky princes lived for a long time during the summer in Menelas's guardhouse.
The old guardhouse was not demolished but rebuilt in 1834 according to a project by architect I. Charlemagne under the supervision of architect I. D. Dusar de Nevil. This house was most often used before the revolution as summer accommodation for court physicians. The lions "guarding" it now appeared only after World War II, when Znamyonov, being the chief custodian, found them in Leningrad and transported them to Peterhof. These lions served as supports for the wooden columns of the Lion Pavilion in Ekateringof (architect Monferran). One of these pairs of lions, after many relocations, was transferred to the Directorate of Palaces and Parks of Petrodvorets in July 1970.
Opposite the palace at the entrance to Alexandria, a stone Gothic guardhouse was built with metal entrance gates. The walls of the guardhouse are pierced with narrow Gothic windows, and the top is decorated with turrets and a battlement parapet.
The building is adorned with the coat of arms of Alexandria – "a shield with a naked sword passed through a wreath of white roses." The romantic knightly coat of arms was invented by the poet V. A. Zhukovsky. This coat of arms is present on all the main buildings of Alexandria.
Sources:
https://www.citywalls.ru/house19447.html
Gushchin V. A. History of Peterhof and its Inhabitants. Book III. New Peterhof. Saint Petersburg. 2005. pp. 9-14
Batorevich N. I. Ekateringof. History of the Palace and Park Ensemble. St. Petersburg. Iskusstvo-SPB, 2006. p. 119., anchurian