PETRA

UNESCO describes it as "one of the most precious properties of man's cultural heritage". I would not desaggree after having visited it. The ancient capital of the Nabataeans has been inscribed in the World Heritage list since 1985; has also been declared one of the New Seven Wonders of the World by world-wide voting in 2007.
Petra is a grandiose festival of rock and architecture in an unique combination: the "buildings" are indeed not built, but escavated on the rock. I think I can call it "negative architecture".
In 1845 John William Burgon wrote a long poem about Petra, which apparently he never visited and had just heard described by others:

But rose-red as if the blush of dawn,
that first beheld them were not yet withdrawn;
The hues of youth upon a brow of woe,
which Man deemed old two thousand years ago,
match me such marvel save in Eastern clime,
a rose-red city half as old as time.

I took a lot of pictures during my visit. Instead of the classical ones, showing the frontage of buildings or the tombs, I add to this note two more unnusual ones, which portray the strange colours of the rock and the rare configuration of the east entrance, which acts as a waterway when there are (rarely) heavy rains. You will note that there is more than the red and rose Burgon referred to. He should have visited Petra for the sake of the colours' truth