Should we build new cities at sea?
As the world faces up to the threat of rising sea levels, could building new cities entirely out at sea offer an alternative way of living?
That is the idea being tested in the Netherlands where huge swathes of land already lie below sea level.
Architects are creating prototype neighbourhoods of sustainable floating houses which could withstand future flooding.
Anna Holligan has been to see the technology and find out if it could work in other countries too.
Video journalist: Jens van Pieterson