This park should not be confused with Alexander Park in St. Petersburg and Alexander Garden in Moscow.
The Alexander Garden lies along the south and west façades of the Russian Admiralty in St. Petersburg, parallel to the Neva River and Admiralty Quay, extending from Palace Square in the east to St. Isaac's Cathedral in the west. The English park is named after Alexander II of Russia who ordered some 52 species of trees to be planted there. It was formerly known as the Admiralty Boulevard, the Admiralty Meadow, and the Labourers Garden.
The garden was designed by Luigi Rusca in 1805. William Gould, an English-born gardener, was hired to raze the southern ramparts of the Admiralty Fortress, replacing them with four lime-tree alleys. The moat of the fortress was filled in 1819, making room for additional lanes.
Wikipedia https://en.wikipedia.org/wiki/Alexander_Garden_(Saint_Petersburg)
Address 14 Адмиралтейский проезд, Санкт-Петербург 190000, Russia
Coordinates 59°56'10.802" N 30°18'22.63" E