In his talk at TEDx Vilnius, Koen Olthuis compares the cities of today with those at the turn of the 20th century: "cities are not full, we just have to search for new space... they made elevators and built a vertical city. We have to do exactly the same, but our generation has to look at water." With that in mind he looks at the top 10 reasons that floating cities are becoming a more popular idea, including: they provide solutions for topical issues such as flooding and sustainability; they can be used as 'plug in' travelling global amenities, useful for things like Olympic Stadiums; or could even allow us to rearrange urban areas.