I'm going through the individual .map files. It's interesting to see how Bungie originally named the files ... and what 343 Studios (writers) decided to call them.

"The Pit" = Cyberdyne (from Terminator, lol)
"Valhalla" = Riverworld
"Sandtrap" = Shrine
"Last Resort" = Zanzibar (from H2)
"Highground" = Deadlock
"Orbital" = Space Camp
"Rat's Nest" = Armory
"Standoff" = Bunker World
"Cold Storage" = Chillout (from H2)
"Citadel" = Fortress
"Blackout" = Lockout (from H2)
"Heretic" = Midship (from H2)
"Avalanche" = Sidewinder (from H1)
"Foundry" = Warehouse