An interesting mix of structures here. In the background left and foreground right, one can see towers on which appear to be mounted lights, like stadium lights. The other tall objects could be construction cranes.

In the background on the right is a smooth structures that looks very Forerunner-like, quite a bit like the beam towers seen on Halo installations.

In the foreground, the tanks look abandoned. The fact that humanity does not know the origin of the force that laid them low may indicate that either no traditional war was ever fought, or that it happened so long ago that there is no living memory of it.