The Baltic Sea is one of the fascinating areas in the world â with a rich history, an unspoiled nature in a safe and secure environment. The Baltic Sea is one of the fascinating areas in the world â with a rich history, an unspoiled nature in a safe and secure environment. Take a Baltic Sea cruise and youâll soon discover that the capitals of the Baltic still retain an imperial air about them and combine old-world charm with a thriving contemporary arts and entertainment scene. Each with their own distinctive allure, these remarkable cities have architectural styles that span the ages. The jewel in the Baltic crown, St. Petersburg with its treasure filled Hermitage is an undeniable highlight of any Baltic cruise, though many other riches lie elsewhere; in Tallinnâs medieval architecture, Stockholmâs smattering of islands and perhaps, most surprising of all, in Kristiansandâs great beaches.