Dutch engineers have unveiled plans for a £7.4 billion underground city providing one million square feet of underground retail, leisure and parking facilities.
what we are doing is building a city under the city by using a new construction technique, which will not interfere with street traffic
Amsterdam was originally built on drained, swampy marshland and many of the classic Dutch gabled houses along its canals are still precariously supported by underground wooden beams.
canal water will be temporarily pumped out in order to start construction beneath.
Amsterdam sits on a 30-metre layer of waterproof clay which will be used together with concrete and sand to make new walls
Once we have resealed the canal floor, we will be able to carry on working underneath while pouring water back into the canals
The project has been approved by Amsterdam's city council. Construction work, lasting up to 20 years, is expected to begin in 2018.
clipped from: www.treehugger.com 
