This 2,000-year-old city, where the Teutonic Order founded one of its first commanderies in the 13th century, lies on the convergence of the Moselle and Rhine Rivers.

Ho Chi Minh City, formerly known as Saigon, is the most populous city in Vietnam at 9 million people. It is an enticing mix of the old and new, with European architecture due to French colonization to towering skyscrapers and modern shopping malls.

Cuba is a multicultural nation and the largest island of the West Indies. Its waterfront capital is Havana, a musical, scenery-rich city that is the center of commerce and tourism. Walk the Malecon of Havana, marvel at the artworks in the Museo Nacional de Bellas Artes, and go for a refreshing swim on Cayo Coco in central Cuba.

Rapid City is the gateway to iconic Mount Rushmore National Memorial and a delightful stop for your next trip to South Dakota.

Washington D.C. is the capital of the United States and home to some of the country's most iconic landmarks and monuments, including the White House, the Washington Monument, the Lincoln Memorial, the Smithsonian National Museum of Natural History, and the Capitol Building.