cs_mansion is one of the hostage rescue maps of the first public Counter-Strike beta from June 1999. The terrorists guard three hostages inside a two-storey mansion, and the counter-terrorist team starts across the lawn, with open ground on every approach to the house.

The file is the beta-era original. The worldspawn still names the hgrunt and scientist teams of Half-Life, there is no dedicated rescue zone (the hostages are walked back to the CT spawn, the way the early game handled it), and the map uses only the stock textures, so the download is a single .bsp.