Luxembourg City, the capital of the Grand Duchy of Luxembourg, is a stunning blend of medieval charm and modern sophistication. Perched atop dramatic cliffs and surrounded by deep gorges, this city offers a unique and breathtaking landscape. The UNESCO-listed Old Town is an essential starting point for visitors, with its ancient fortifications, narrow cobblestone streets, and grand squares.

Caernarfon, a town in northwest Wales, is famed for its medieval heritage, most notably Caernarfon Castle, a UNESCO World Heritage Site built by Edward I in the late 13th century.

Bulgaria is a republic in southeastern Europe. The capital and largest city is Sofiya. Bulgarian culture has been influenced successively by Byzantine, Greek, Russian, and Western cultures.

The capital of French Polynesia, Papeete is a veritable island paradise with bright cerulean waters, iconic overwater bungalows, and palm trees galore.

Evidence of our nation's birth abounds in Boston, a hub of revolution that is essentially the oldest city in the United States. Visitors are compelled to walk the 2.5-mile Freedom Trail around the city center, and bear witness to 16 historical locations related to the history of America.