These are some concept illustrations for production designer Rick Heinrichs and director Scott Derrickson.
I helped with the design of both towers together with our set designers in London going back and forth until
they settled with a version that worked better for the script.
The bottom half of the towers were built outside and the top part on stages in Leavesden Studios.
Special thanks to Brian Burke at gravityb.com for scanning the military characters
and Lise Montsion for posing as Drasa.
Please check also the works of my good colleagues Nathan Schroeder and Robert Castro who worked in the film if you'd like.
Nathan Schroeder http://www.nathanschroeder.net/Gallery
Roberto Castro https://www.artstation.com/robertofc