The American protocol is usually to name developments after what was once there, and as such the natural feature currently present is now to be called the water basin and I presume the structure will be known as the Oasis.
Seriously, micro climates are powerful tools if done right. I remember taking a tour of the Penang botanical gardens on a typically hot day. The tour went through a block of remnant rain forest and the temperature seemed to drop ten degrees. It might have been just the trees sucking up the humidity, but a building like this would be a great way to show that you can live in environments like that.
There’re quite many out there. One turned into a hightech building, which in turn is also a pretty interesting albeit artificial ecosystem, won’t matter. It’s not the last one anyway.
the Sahara is pretty darn big, and getting bigger everyday. Just in the time since John Glenn first orbited the earth, it has expanded by another 250,000 sq mi to now cover over 3.6 million square miles.
I thought my memory from grade school textbooks was off, but nope: it really is bigger than when I studied geography in school. Noticeably. Wow.