Quazen blog has a list of 9 incredible architectures sculpted out of rocks:
China has many a Buddha dotted throughout its extraordinary landscapes but the Giant Buddha of Leshan is unique in that it was carved directly out of the cliff face - just look at the people at the feet of the statue. The sculpture, which is seventy one meters (or over three hundred feet) tall dwarfs the tourists that flock to see it. It is positioned so that it faces Mount Emei and stands at the meeting place of three rivers. Although the Government of China has promised a restoration program, the statue has suffered from the effects of pollution, particularly over the last twenty years. Fortunately, the statue was not damaged in the Sichuan earthquake of 2008.
From the Upcoming ueue, submitted by taliesyn30.
He looks like the Scarecrow from the Wizard of Oz.
Just to create something like that Ethiopian church, for example. How much might that cost, and how *long* would construction take? (Would the modern tools/tech make any difference?)
I also wonder if there are any contractors who can specialize in stuff like this....