Peterhof

In the time of Peter the Great, the sea floor just north of the Peterhof site and to the east toward St. Petersburg was too shallow for either commercial ships or warships. However, to the west of Peterhof, the sea floor dropped off to be deep enough for sea vessels. Accordingly, when Peter the Great decided to build St. Petersburg at the eastern end of the Gulf of Finland, he first captured the Kotlin Island clearly visible from the Peterhof site just to the northeast in the middle of the Gulf. At Kotlin Island he would build the commercial harbour for St. Petersburg as well as the Kronstadt fortifications across the 20 kilometres of shallow sea to provision and defend the Navy that he would build.