The strangest place you can heal
This is the most interested I've ever been in a couple chargers.
Prototype screenshot courtesy of Combine Overwiki's upload of hl-tentacle.mpeg. Comparison screenshot taken by myself.
NOTE: I am not including the invisible HEV charger in Apprehension due to this more obviously being an unusual map decision as opposed to an outright mistake.
BGM: Deus Ex - Tunnels (Unused)
Map is c1a4i.