The Red Tower
St. Louis, Missouri
Built as a way to equalize water pressure in the 1880s, the Red Tower is essentially just a pipe connected to the water main, jutting 194 feet straight up out of the ground, surrounded by a fancy brick exterior. When the local pressure was too high, water would rise into the pipe, and vice-versa. No known pressure surges were strong enough to turn the Tower into the World's Tallest Fountain.
The Red Tower was retired from service a century ago, and escaped several subsequent efforts to knock it down. Its exterior was restored in the 1970s, but unfortunately an interior spiral staircase that led to a pipe-top observation deck has never been replaced.