Ecohousing - a lost art

I've just visited the towns of Nalut and Ghadames on the edge of the Sahara both several hundred years old. What's interesting is that they both incorporate walls with high thermal mass for Passive Solar heating (and cooling). Libyan's in fact claim that Ghadames has the oldest Air conditioning system in the world.

These aren't the only Eco features. The houses also had a sophisticated water management system and even their very own form of composting loos. Funny how we're only just rediscovering these techniques!
Ironically the towns are now all but deserted with the government having built new 'improved' versions outside the city walls in the 80's. Apparently the new concrete homes work nowhere near as well!