The tokamak reactor in the foreground (you mean, you didn't recognise at once that that's what it was?) is composed of five toruses (tori?). The innermost was set to Light in the materials editor, the next one out is transparent, and the third uses the Steel Cage material. Because this is effectively flat, two smaller toruses were added to produce the top and bottom of the frame.

The rest of the scene consists of 'buildings' made by carving up pyramids using Booleans, and a 'monorail track' also built from lightly-sculpted primitives. The chain link fence in the foreground uses a PICT from the Bryce 2 CD.

The atmosphere preset used for this image is available, saved as a Bryce scene file.

Mars sky preset [10K]