Take a tour of Peter and Paul Fortress in St. Petersburg, Russian Federation – part of the World’s Greatest Attractions travel video series by GeoBeats. Built by Peter the Great with the purpose of defense, this fortress is the first pivotal structure of St. Petersburg. Initially a fortress, then a political prison for almost 2 centuries and now an ensemble of architecture, engineering, and history. Nearly 125 meters tall is the cathedral bell tower which was first to be constructed. The cathedral is the oldest church of St. Petersburg. It is also the official burial spot of Imperial families. As a tradition here, even today, you can hear a cannon shot at noon every day. The start of fortress' construction on May 27, 1703, is commemorated as the founder day of St. Petersburg.