This 100 brush Base map uses textures from Quake 2, as well as a couple of composites from CZG.
CZG's description:
"My entry for 100 brush V2.00 contest:
Biotoxin - Where toxic waste comes to die, and to be pumped out into earth's ecosystem.
... Built with WC1.6, compiled with WQbsp, Tyrlite...