Actually yes, there is a Black Mesa. And just like in the game, they are researching aliens over there. The government offers daily tours, but you usually have to call a week in advance to get the tickets. But since they're free, you really can't complain, right?
actually, there probably IS such a place as black mesa.. in UTAH, or Texas somewhere. Allthose cowboy films you see withthe big mushroom shaped rocks in the bacground. they're mesa. .
OTOH "black Mesa" as in the nice high tech research facility probably doesnt exist.
probably.
the same way that Area 51 doesn't exist.
and white sands is just a propulsion lab.
and the british C&C bunker is just "underground tunnels".
and the white hall nuclear bunker is just used for storage.
whatever provides positive bouyancy for your aquious transport vehicle