If you're planning a cruise to Scandinavia and Russia one of the highlights is sure to be an overnight stay in St. Petersburg. Also known as the "Venice of the North," this canal-lined city boasts an abundance of historic, cultural, and architectural sites. One of its most significant cultural attractions is the sprawling Hermitage Museum a must-see collection of six historic buildings including four museums, a multitude of rooms, and more than three million wildly impressive exhibitions of artifacts, paintings, and statues. One of the largest museums in the world, the Hermitage is so vast that it could take years to explore.