St.-Petersburg map by GoogleMaps engine. This allow: change of map scale; switch between scheme and satellite view; streets and houses search - in most of cities, towns, and some villages of the World. If you can't find something, try Yandex map of St.-Petersburg or St.-Petersburg map by OSM.
Drag the human icon from map left-top to the place you interest - to switch to virtual panorama streets view (exist on streets, marked blue during the drag)
Use toddler "+ -", or mouse weel over gmaps area, if you want to change map scale; for switch view to satellite photos - click "satellite" button on the map top-right.
See also capital of St.-Petersburg: Saint Petersburg map