From grand castles to resplendent cathedrals, Tallinn’s Old Town neighborhood, a UNESCO World Heritage Site, is the perfect place to begin exploring. Enter through Viru Väravad, or Viru Gate, the former fortress whose remaining two towers beckon you into the heart of the city.

South America, the fourth largest of the earth's seven continents (after Asia, Africa, and North America), occupying about 17,819,100 sq km (about 6,880,000 sq mi), or about 12 percent of the earth's land surface.

Situated on the shore of Lake Titicaca, Puno is referred to as the folkloric capital of Peru due to its artistic and cultural expressions, particularly dance. Notable landmarks include the Andean baroque-style Puno Cathedral and the Yavari, a 19th-century steamship. Products created from alpaca, llama, or sheep wool are a signature of the area, as well as musical instruments like the siku.

Antigua, Guatemala's prized colonial monument, is just an hour from Guatemala City, and a pleasant alternative to staying in the capital. Good walking shoes are needed for its cobblestone streets. The most spectacular time to visit is Holy Week, when processions walk on handmade sawdust carpets with beautiful floral and geometric designs.

Ulm, Germany, a picturesque city on the banks of the Danube River, offers a rich tapestry of history and modern charm. Dominating its skyline is the Ulm Minster, home to the tallest church steeple in the world at 161.5 meters (530 feet). This Gothic masterpiece invites visitors to climb its 768 steps for a breathtaking panoramic view of the city and the surrounding countryside.