Its a series of giant tubes

No in this case it really is a series of giant tubes, beneath the streets of Tokyo. You can go in as a tourist and see this crap for real. It looks like it is out of half life or something weird and its really used for removing a whole bunch of water from under tokyo during the typhoon season. Giant 50 metre tubes with giant pumps that power through the super happy fun slide of water than inundates everyone's favourite city.



Thanks Mykl!