1. St. Peter’s Basilica, Vatican City. St. Peter’s is a triple threat — it’s the centuries-old seat of Catholicism, home to one of the finest art collections in the world, and a visual feast in its own right. Found it overhyped and overcrowded when you visited? Here’s a hint: show up early. At 8am, you’ll have the place to yourself./ Photo: edbrambley

2. Golden Temple, Amritsar, India. Amritsar’s Harmandir Sahib, or “Golden Temple,” is the holiest site in Sikhdom. It’s located in the Punjab, in north western India. / Photo: estetika

3. Kek Lok Si Temple, Penang, Malaysia. Kek Lok Si’s giant Kwan Yin statue dominates the road to Georgetown, the main city on Malaysia’s Pulau Penang, and the various segments of the temple proper seem to spill down the mountainside. I’m sure there are plenty of more famous Buddhist temples in the world, but this one has stayed with me for years. / Photo: shanemcg

4. Mecca, Saudi Arabia. Mecca is the historic and spiritual heart of Islam. Millions of devotees flock to the vast mosque complex each year for the hajj, the world’s largest pilgrimage. At present, Mecca is open only to hajjis — so for now, unless you’re a practicing Muslim, file this one under “daydreams.” / Photo: Wiki Commons

5. Sagrada Familia, Barcelona, Spain. Gaudi’s unfinished masterpiece (under construction for 127 years and counting) is a mixed-up fantasy of shapes and colors, light and space. The scaffolding and other signs of construction only add to the awesome confusion of a holy sensory overload. / Photo: jurvetson

6. Aya Sofya, Istanbul, Turkey. Istanbul’s Aya Sofya (also called the Hagia Sophia) began life nearly 1500 years ago, as a church. 1000 years later, after the Muslim conquest of Turkey, it was re-invented as a mosque: its mosaics were plastered over, and replaced by Islamic calligraphy. Today it’s a de-consecrated museum — the mosaics are being slowly uncovered, and displayed alongside their later replacements, showing the literal layers of religious history at the junction of Europe and Asia. / Photo: vshioshvili

7.Jain and Hindu Temples, Khajuraho, India. If you’ve walked the tourist trail in India, chances are you already know Khajuraho — the erotic sculptures that cover the walls of the village’s temple complex are a big hit with visitors. / Photo: sankaracs

8.Il Duomo, Florence, Italy. Officially known as the Basilica of Santa Maria del Fiore, Florence’s “Duomo” (Italian for cathedral) has two ways to awe you: First, there’s the massive dome, the largest ever to be constructed in brick, and one of the first major domes to be constructed since Roman times. And second, there’s the facade, an intricate marble pattern in pink, green and white. Honestly, I don’t think I’d ever get tired of looking at this building. / Photo: chrisbuckridge

9.Great Synagogue, Budapest, Hungary. Also known as the Dohany Street Synagogue, Budapest’s Jewish temple is the second largest in the world. Theodore Herzl grew up next door. / Photo: harshilshah

10.Great Mosque, Xi’an, China. Xi’an’s Great Mosque was built more than 1300 years ago, and still serves local Chinese Muslims today. If you’re expecting domes and minarets, though, don’t hold your breath — the complex is built entirely in the traditional Chinese style, and — visually — has more in common with the Forbidden City than with Mecca. / Photo: andreweland

11.Rock-Cut Churches, Lalibela, Ethiopia. Lalibela is a hub for the Ethiopian Orthodox Christian community, and the area is home to a cluster of rock-cut churches — that is, holy buildings carved downward into the ground, instead of built upward from ground level. Ethiopia’s Christians have a history all their own, and (as you see below) an architecture to match. / Photo: herr_hartmann

12. Cathedral of Rio de Janeiro, Brazil.This modern-day cathedral may not be entirely to my taste, but there’s no denying the power of a church built 250 feet high, with floor-to-ceiling stained glass windows climbing 210 feet. / Photo: soldan