China has built the world’s largest single-dish radio observatory (FAST) at a cost of $171 million. The telescope, also known as the ‘Eye of Heaven’, took 5 years to build in a remote area in southwest China. Its 500m-wide dish is made up of ~4,400 individual, adjustable aluminum panels. – WTF Fun Facts
WTF Fun Fact – Five-hundred-meter Aperture Spherical Radio Telescope
Actually, no. The current record holder for the biggest swimming pool is San Alfonso del Mar, and it is more than twice as wide as this observatory: https://en.wikipedia.org/wiki/San_Alfonso_del_Mar
and will become the worlds largest swimming pool during a massive rain storm!