ESO's Paranal Residencia under construction

The historical photograph shows the Residencia under construction at the end of 2000. The building was designed by German architecture firm Auer+Weber, and is based around a subterranean L-shape. The building materials have the same colour as the desert, to help it blend into the landscape, and the partially completed central area of the Residencia is reminiscent of an amphitheatre, with stone tiers open to the cloudless sky. 

This is the historical image from the Then and Now comparison Picture of the Week, An Oasis for Astronomers.