Thames Barrier, E16

(1982) 520 m long and protecting 125 square km of valuable real estate and many people. This is a stunning piece of Architecture and a remarkable feat of engineering. Sea levels continue to rise by 2 feet per century through a combination of rising sea levels from global warming, Britain tilting from the ice age and London sinking on its clay foundations. More installations like the Thames Barrier will be required to protect low lying populated areas around the world.