This enormous hall is an underground drinking-water reservoir in Budapest, Hungary. It was built between 1869 and 1871 to provide healthy water for the inhabitants of the city, and it is still in operation.
Its water level is usually around 8 metres, but 1-2 times a year the Budapest Waterworks opens it to the public.
It is entirely made of bricks, its walls are half a metre thick, surrounded and supported by many metres of compressed clay, and obviously watertight.
This fountain-looking contraption is one of the in- and outlets of the pool, water flows inward on the top and flows outward at the bottom. There are two of these structures inside the reservoir.
Although most of its duty has already been taken over by more modern concrete reservoir pools around the city, this old building still stands the test of time.
