Gotland, Sweden’s largest island, sits in the Baltic Sea and feels like a world of its own. Its main town, Visby, is a UNESCO World Heritage site and one of the best-preserved medieval towns in Northern Europe. Surrounded by a 3.5-kilometer stone wall with original towers still intact, Visby once served as a key Hanseatic trading hub. Visitors can walk along cobbled streets lined with rose-covered cottages, explore Gothic church ruins, and climb up the city wall for views over the harbor.

Nestled on the northern coast of Iceland's Snæfellsnes Peninsula, Stykkishólmur is a charming coastal town known for its scenic beauty and maritime heritage. Often referred to as the gateway to the Westfjords, Stykkishólmur is the ideal base for exploring the stunning landscapes of this less-traveled part of Iceland. The town's picturesque harbor, lined with colorful houses and fishing boats, offers a quintessential Icelandic coastal experience.

Alberobello in southern Italy’s Puglia region captures the imagination with its distinctive trulli houses. These structures were built using a dry-stone technique passed down over centuries, without mortar or cement, and their unique form comes from layer upon layer of limestone nestled from nearby fields. Alberobello’s trulli are so remarkable that in 1996 the historic center was inscribed as a UNESCO World Heritage Site, where more than 1,600 of these buildings still stand.

Londonderry, often called Derry, is a city steeped in history and charm, uniquely surrounded by remarkably well-preserved 17th-century walls. In fact, it holds the title of being the only completely walled city in all of Ireland. Strolling along these ancient ramparts offers visitors not only a glimpse into the past but also breathtaking panoramic views of the winding River Foyle and the lively streets below.

Guanajuato, a UNESCO World Heritage City nestled in the mountains of central Mexico, is a place where history is built into every hillside alley and underground tunnel. Today, visitors can still tour La Valenciana Mine, where centuries-old tunnels and original mining equipment offer a glimpse into the city's wealth-driven past. The nearby Templo de San Cayetano, built by mine owners in the mid-1700s, is a stunning example of baroque design, lined with gilded altars and intricate woodwork.