You can’t really miss it—Florence’s cathedral (Cattedrale di Santa Maria del Fiore) dominates the skyline with that massive red-brick dome. Construction began in the 13th century and continued for nearly 150 years, which is evident in the diverse styles. The outside is covered in pink, green and white marble—oddly beautiful up close. Inside, check out Vasari’s Last Judgment fresco under the dome. If you’re up for the climb (and it is quite a climb), the view from the top is worth the leg burn.

The Arab Baths are a striking example of 12th-century Romanesque architecture, inspired by Roman and Islamic bathhouse traditions rather than built by them. Designed during a period of Christian rule, they served as public baths for Girona’s diverse medieval community, blending functional elements from Roman thermae, Muslim hammams, and Jewish purification rituals. The centrepiece is the apodyterium (changing room), a sublime octagonal space crowned by a dome and supported by slender columns, where a central pool reflects light from above. Other rooms — the frigidarium (cold bath), tepidarium (warm room) and furnace-heated caldarium (sauna) — showcase sophisticated hydraulic engineering. Despite damage during sieges and later use by Capuchin nuns, the baths were meticulously restored in the 20th century. Today, they offer a quiet glimpse into medieval daily life and the cross-cultural exchanges that defined the era.

A network of eerily beautiful underground tunnels extends for several kilometres near the village of Santa Rosa. They formed when the outer layer of a lava flow solidified, allowing the interior to continue flowing, leaving the hollow lava tunnels for travelers to explore freely. They are vast and have electric lighting, making them easy to explore independently, or with the help of hired guides.

One of the oldest and largest mosques in China, the Great Mosque of Xi'an is a fascinating blend of Islamic and Chinese architectural styles. Built in the 8th century, it’s a stunning example of how different cultures can come together in harmony. As you wander through its peaceful courtyards, you’ll spot pagoda-like minarets, intricately carved wooden beams, and beautiful Arabic calligraphy—all set against a backdrop of serene gardens. The mosque is still an active place of worship, offering visitors a chance to witness the unique fusion of Chinese and Islamic traditions.