Vilnius University boasts that it is the oldest university in Eastern Europe. It's unusual in that, unlike centuries-old universities in other cities, its buildings are interconnected on one central campus rather than scattered throughout the historic urban center. This arrangement makes touring the university easy, at least if you have a guide or a pretty good map, because it's just as easy to get lost in the maze of corridors and courtyards that make up the Renaissance, Baroque, and Classical architectural complex. Visit the library's hallowed halls to view impressive displays of ancient books, or step inside the solitude of Sts. John Church to see elegant Baroque alters that, despite being made of marble, look lighter than air.
Hall in Vilnius University Library photo credit: Kerry Kubilius, licensed to About.com