Dating back to 1703, Elfreth’s Alley is often hailed as the oldest continuously inhabited residential street in the United States. Go back in time by walking down its narrow, cobblestone lane, where Federal and Georgian-style homes still stand proudly as relics of a bygone era. At numbers 124 and 126, you’ll find a small museum offering a glimpse into the daily lives of working-class Philadelphians during the colonial era.

Downtown Houston has been stepping up its game, and it’s a great place to explore on foot. Hop off the METRORail and you’re in the middle of it all—Broadway shows at the Hobby Center, Astros or Rockets games, live music, and some seriously good food. Discovery Green is always buzzing with events, while Market Square Park has a more laid-back vibe with historic charm and cozy bars. And if the Texas heat gets to you, take a detour through the downtown tunnel system—a hidden maze of air-conditioned walkways with cafés, shops, and a steady stream of office workers on their lunch breaks.

Founded in 1330 and located on the banks of the Daugava River, the Riga Castle is one of the country's most prominent medieval castles. Throughout its history, it has suffered significant damage and seen various rulers and wars. After numerous reconstructions, it is a typical sample of late Classicism architecture. Currently, it serves as the official residence of the President of Latvia.