1. Montserrat Monastery, Catalonia, Spain.
I'm sorry, what?! Is that a mountain?
2. Mont Saint Michel, France
3. Al Khazneh or "The Treasury" at Petra, Jordan.
4. Cliff Palace, Mesa Verde National Park, Colorado
Why build a roof when you could just use a cliff?
5. Potala Palace, Chengguan, Tibet
6. Leshan Giant Buddha, China
Why yes that is a 233 FOOT TALL BUDDHA CARVED INTO A MOUNTAIN!
7. Angkor Wat, Cambodia
If it's cool enough for Lara Croft, it's cool enough for me.
8. Bet Giyorgis Church in Lalibela, Ethiopia
Oh no biggie, you just carved an entire church INTO solid rock.
9. Chandi Bori Well Abhaneri, India
10. The Alhambra, Granada, Spain
No one can build quite like those Moors!
11. Bagan Temples, Myanmar
12. Pyramids of Teotihuacan, Mexico
13. Wooden Churches of Kizhi Island, Russia
14. Suspended Temple of Mt. Hengshan, China
15. Shibam Mud Houses, Hadhramaut, Yemen, sometimes referred to as "mini mud Manhattan."
16. Cave Monastery, Vardzia, Georgia
Cliffside cave dwellings are about as badass as you can get. Props, Georgians.
17. Village of Monsanto, Portugal built between natural boulders.
See a boulder, build a village...? WHY THE HELL NOT?