Among London's many problems as it grew at the beginning of the nineteenth century was travel between the two banks of the river Thames, which held important ports that could accept shipping coming up the river from the channel. Bridges would interfere with that important trade, so in the years of the 19th century engineers began to examine the only other option: instead of going over, going under the river.
On September 22, 1953 a new kind of construction was fully opened for the first time in Los Angeles. The Stack is an LA icon that changed the way the world builds its highways.