Someday in the future, we will run out of usable land on earth and we will start to build our future cities on the sea. I imagine modular floating cities like this one I designed for the Cities of the Future design contest.

About my City of the Future:
The floating city will be built out of hexagonal pontoons that are connected by bridges above sea level. Each pontoon can be a self-sustaining island, or be connected to a larger city. Pontoons can have housing units, hotels, offices, beaches, parks, harbours, musea, factories, shopping malls, etc. The interconnected pontoons will form a walkable city above sea level, while faster public transport systems will be available below for longer travel distances inside the city. 
 

The hexagonal pontoons will be manufactured on land by massive 3D-printers, which can print all the required infrastructure right into the structure. The bridges can also be 3D-printed in stainless steel.

About the model:
Pontoons are printed separately and connected with hinged bridges which simply snap into place. There is a recess in the side of the hexagon where unused bridges can be tucked away. This design allows for some flexing and independent motion of the hexagons. 
I originally designed the pontoons to be able to actually float on water. They each have a 5mm toothed hole in the bottom where you can insert a screw to function as a counterweight for buildings that may be a bit top-heavy. This system works pretty good for the smaller buildings, but not so much for the larger towers. I had so much fun designing the larger futuristic looking towers that I forgot to keep an eye on the total mass of each tile.  
I printed most models in multiple colors with simple filament changes at certain layers. This way hardly any filament is lost and it still shows off the extra details in the designs.

Design your own City of the Future:
You can print any of the models in the print profile in any colors you like. Print a set of bridges and have a lot of fun assembling your own dream city. 
You can also add your own designs! Download the blank pontoon model (3MF or STP provided) and add your own futuristic building design on top.

You can also support my work on Ko-fi! 
Or, if you're interested in selling physical prints of my designs, check out my commercial license options there.