Rough buttresses rose out of the ground to brace the tower's sides. The buttresses were topped with balconies that were dark and indistinct. There didn't seem to be quite enough windows. And high up, where those few windows faced the sky, strange lights were pulsating in unsettling colors, and in a rhythm that seemed somehow...wrong.
A deep throbbing shook the ground under the tower in a completely different, but no more comfortable, rhythm. The drumbeat of the sound and the flickering of the lights combined into a dissonance that made their heads hurt.
In other words, this was a fairly normal Precariously Situated Research and Development Installation, Second Class, Type C. The kind that often exploded without warning, leaving a big smoking crater.