Hoover Dam
Hoover Dam, once known as Boulder Dam, is a concrete arch-gravity dam…
Colosseum
The Colosseum, or the Coliseum, originally the Flavian Amphitheatre i…
Bell Rock Lighthouse
Bell Rock Lighthouse is the world's oldest surviving sea-washed l…
London Sewerage System
The London sewerage system is part of the water infrastructure servin…
Panama Canal
The Panama Canal is a 77-kilometre (48 mi) ship canal in Panama that …