Why did peter the geat want to build st. petersburg

The reign of Peter, who became sole czar in 1696, was characterized by a series of sweeping military, political, economic, and cultural reforms based on Western European models. Peter the Great, as he became known, led his country into major conflicts with Persia, the Ottoman Empire, and Sweden. Russian victories in these wars greatly expanded Peter’s empire, and the defeat of Sweden won Russia direct access to the Baltic Sea, a lifelong obsession of the Russian leader. With the founding of St. Petersburg, Russia was now a major European power–politically, culturally, and geographically. In 1721, Peter abandoned the traditional Russian title of czar in favor of the European-influenced title of emperor. Four years later, he died and was succeeded by his wife, Catherine. hope this helps

The one that most represents the earths mantle would be the skin since the mantle is the upper part of the earths depths which is just like the skin of an apple.