Sea City 2000 (1979)
Today we have more from the great book Future Cities: Homes and Living into the 21st Century.
The Sea City 2000 shows some great paleo-future technology such as the dish-shaped antenna that "beams microwave energy, generated by solar cells, to a receiver on the nearby coast."
The bottom right corner shows a Buckminster Fuller design for a floating community. His design includes shops, schools and homes for 5,000 people.