A city in perpetual forward motion, Abu Dhabi greets visitors with gleaming skyscrapers and opulent Islamic architecture. There is much to see here, from the recently opened Louvre Abu Dhabi to the gigantic Sheikh Zayed Grand Mosque, with its white marble splendor. Beach life and turquoise waters can be found on Saadiyat Island, Al Bateen and Corniche Beach.

Plovdiv, one of the oldest continuously inhabited cities in Europe, carries over 8,000 years of history layered into its streets. The Roman Theater, still in use today, was discovered by accident in the 1970s and now hosts operas and concerts overlooking the Rhodope Mountains. Nearby, visitors can walk the remains of a Roman stadium buried beneath the main pedestrian street, where modern shops and cafés stand above ancient foundations.

Together with neighboring Glacier National Park in the United States, Waterton Lakes National Park is part of the world's first international Peace Park, which was recognized as a UNESCO World Heritage Site in 1955. The Waterton-Glacier Peace Park protects an important biological crossroads where the Rocky Mountains reach their narrowest width. Waterton's bedrock is much older than that of the mountains to the north found in Jasper and Banff.

Nova Scotia covers an area of 21,425 sq. miles, and Halifax is the capital. This is an area rich in history — Gaelic is still spoken here in some areas by descendants of the early settlers. The coast is peppered with fishing villages, and inland the climate boasts sprawling valleys and rocky headlands.

Located in Pennsylvania, Pittsburgh is one of the oldest cities in the nation.