Time is a great teacher, but unfortunately it kills all its pupils - Hector Berlioz
The technical name for it is Underground Container for Active Telecom Equipment, but bunker fits in much better with the mountain fortress motif geeks seem to love. Marketers call it Nemo.

So, why do they make it? It is meant to house telecom equipment in areas that do not allow the typical above-ground 'cans'. You can either rent someone's basement for a huge fee or simply bury it. Burying generally makes it a bit more tamper proof than a flimsy lock, if you can figure out how to open it, it is still big and heavy.
The internal compartment is meant to dissipate up to 1000W of power through the ground, so cooling is taken care of. The whole structure hydraulically raises up so you don't have to dig much to get to the goodies.
Everything is solid steel construction, and I mean solid. It looks like you can go at this all day with a big hammer and not end up accomplishing much. It gets those ugly off-green cans that Qwest forgets to lock every 4th time they open it out of your line of site, and makes the world a happier place. Survival nuts take note, this isn't really fit for (live) people.µ