Blue Bridge (Kronstadt)

The Blue Bridge in Kronstadt is a three-span metal bridge with a swing movable span structure from 1874. A copper plate with a horizontal line, which is the zero of the Kronstadt tide gauge, is fixed on its abutment. It is from this level that depths and heights are measured in Russia, and in 1946 it was adopted as the initial level of heights for the entire country. You can walk from the Naval Cathedral to this bridge in less than 15 minutes.