SIX PLAYS: Quake II Old Skool - Exterior Infiltration 

Map name:
Exterior Infiltration by Marty Howe
From the README:
A recon mission over a Strogg Pumping Station has resulted in your
craft being shot down. Most of the team has perished. Littered bodies
mark their attempts at infiltrating the Stronghold to seek an exit.
Hopefully, youll fare better. Find a way inside the main complex, once
inside seek an exit via a mine area. yay! Hold onto your ass :D
Use stealth for this mission, running in guns blazing wont work
There arent hordes of enemies, instead 'interesting combat situations'
You can email be about this level.