The super-skyscraper has been a dream of city planners for over a century. And these plans for mega-structures, if they ever come to fruition, would be some of the most awe-inspiring buildings the world has ever seen. Take a glimpse at the future of architecture in this gallery.

The 13,000 ft (4,000 m) high, 800-story X-Seed 4000 with a 3.7 mi (6 km) wide sea-base to accommodate at least half a million people, designed by Taisei Construction Corporation and Peter Neville in 1995

If These Proposed Skyscrapers Are Ever Built, Cities Will Be Insane

If These Proposed Skyscrapers Are Ever Built, Cities Will Be Insane

(via skyscrapercity)

The 3,284 ft tall (1,001 m) Burj Mubarak al-Kabir Tower, near Kuwait City, Kuwait, designed by Eric Kuhne and Associates, 2006. It will have three interlocked towers to support the overall structure.

If These Proposed Skyscrapers Are Ever Built, Cities Will Be Insane

(via Wikimedia Commons)

The 1,476 ft (450 m) tall Crystal Island, Moscow, Russia, designed by Norman Foster in 2007. It would have a "second skin" to minimize the winter heat loss.

If These Proposed Skyscrapers Are Ever Built, Cities Will Be Insane

If These Proposed Skyscrapers Are Ever Built, Cities Will Be Insane

(via demyment)

The 400-story, 7874 ft (2400 m) high Dubai Vertical City, also known as the Dubai City Tower, by Meraas Holding, 2008

If These Proposed Skyscrapers Are Ever Built, Cities Will Be Insane

This skyscrapers will have an 1312 ft (400 m) high energy-producing spire on the top, and the world's fastest elevators which could travel people at the speed of 125 mph (201 kph).

(via Wall Street Pit)

The 3,200 ft (975 m) high Miapolis in Miami, designed by Kobi Karp Architecture, 2010. This $22 billion self-sufficient building would include an amusement park, a museum, an observatory, a trade center, a rotating sky-lounge, a shopping mall, restaurants, a hotel and a marina.

If These Proposed Skyscrapers Are Ever Built, Cities Will Be Insane

If These Proposed Skyscrapers Are Ever Built, Cities Will Be Insane

If These Proposed Skyscrapers Are Ever Built, Cities Will Be Insane

(via Kobi Karp)

The 3,445 ft (1,050 m) tall Azerbaijan Tower, Khazar Islands, near Baku, Azerbaijan, designed in 2012. It ail lbe the centerpiece of the Khazar Islands, a planned city of 41 artificial islands on 3,000 hectares over the Caspian Sea.

If These Proposed Skyscrapers Are Ever Built, Cities Will Be Insane

If These Proposed Skyscrapers Are Ever Built, Cities Will Be Insane

If These Proposed Skyscrapers Are Ever Built, Cities Will Be Insane

(via Khazar Islands)

Buenos Aires Forum, Buenos Aires, Argentina, a mixed-use development, with a 3,300 ft (1,000 m) tall skyscraper as a centerpiece, designed by Julio Torcello.

If These Proposed Skyscrapers Are Ever Built, Cities Will Be Insane

If These Proposed Skyscrapers Are Ever Built, Cities Will Be Insane

(via Industria Militar Argentina)

Sky City (or Sky City One), Changsha, China, 2013. The prospective builders named Broad Sustainable Building wants to construct the 2,749 ft (838 m) tall skyscraper in only 90 days (not counting the 120 days of prefabrication).

If These Proposed Skyscrapers Are Ever Built, Cities Will Be Insane

The 5000 residential properties in the 202-story building (with the total floor space of 13 million sq ft (1.2 million sqm) will be able to accommodate 17,400 residents.

(via Gizmodo)