Mine Base

The Mine Base is a military base disguised as a mining facility in Costa Rica. Naked Snake passed through this area during Operation Peace Walker. It was apparently, as a front, supposed to mine gold. However, it was a front for the assembly for Peace Walker.

Operation Peace Walker
Main Article

Snake entered here in an attempt to halt Peace Walker's creation, although when attempting to stop Peace Walker from descending down the elevator, he accidentally allowed himself to be spotted by a Kidnapper, thus tripping the alarm and having to neutralize an attack group, as well as Cocoon. Afterwards, he had to sneak through the interior of the mine base while it was on high alert, with some soldiers in the first stretch of the basement corridor rushing in his direction to the elevators to go up to the hangar presumably to back up the soldiers in their search for Snake. Snake then managed to sneak into Peace Walker's hangar, and questioned whether The Boss had any regrets about her final mission. However, he ended up getting caught and captured. Strangelove then proceeded to torture Snake about three times before he managed to escape captivity. Snake then snuck back to the Peace Walker hangar, only to discover that it has been completed, and is forced to fight it and eventually chase it into Nicaragua.