Built in 2003, but looking as if it's from the 19th century, this five-star has a very impressive exterior, with an entrance crowned by a triple arch and a gilded Renaissance logo. Things get cozier inside. The rooms are spacious, comfortable, and decorated in bright contrasting colors, which some might find jarring. The hotel bar is a great place to relax with a drink and take in views of St. Isaac's Cathedral. Both the service and the amenities are reliable, as is typical of Marriotts.