Encircled by Rome, Vatican City is the world's tiniest sovereign country and is smaller than some big-city neighborhoods, covering 110 acres. This is one of the most attraction-rich countries on our list, home to museums, art galleries, gardens and some of the world's most famous religious structures. St. Peter's Basilica and many other historic buildings are visible from its namesake square, which draws a crowd during festivals and papal appearances.
The real highlights for many visitors are the Vatican Museums, which features the Sistine Chapel and other works by the most famous Renaissance artists, as well as collections of early Christian artifacts. The Vatican Gardens (shown here), which contain some of the most impressive plant collections in all of Italy, can be visited only as part of an official tour. But one of the most attractive things about visiting Vatican City is that you can see everything in a single day and still have time to experience the delights of Rome before heading back to your hotel for the night.