The main part of the building, from the centre of which the tower rises, lies parallel to the river with its north side, but has its principal facade on the south, facing the square. The length of this facade is nearly half a mile; and at right angles to it are two sides, stretching from its extremities north toward the river; the east side fronting the Winter palace, and the west the Isaac square and senate-house, and each six hundred and fifty feet in length.
In the above engraving of the square of St. Isaac, the senate-house is seen on the right and the church of St. Isaac appears in the distance on the left. Between them may be seen the colossal equestrian statue of Peter the Great, reduced, however, by the remote distance to diminutive proportions. A nearer view of this statue accompanies the sketch of it a few pages farther on.
see more - St. Petersburg - Imperial Palaces, etc.
Sears, Robert. An Illustrated Description of the Russian Empire. New York: Robert Sears, 1855