SkyriseCities headquarters is closed for the holidays. We'll be back with our regularly scheduled editorial on January 4th, but we've collected skyscraper visions from around the world to give you something to read while we're away.

Massive mixed-use projects like New York City's World Trade Center complex feature designs from some of the world's most influential architecture firms, including Santiago Calatrava and Rogers Stirk Harbour + Partners. Perhaps the largest conceivable project ever to bring together such an influential group of architects is the Dream Hub proposal for Seoul. While the sheer number of international design firms involved lends some credibility to the project, the future of the gigantic development as originally proposed does not look favourable. 

Dream Hub, image via Yongsan IBD - Dream Hub

Dream Hub, officially known as the Yongsan International Business District, would see 66 buildings and 19 skyscrapers constructed. The $28 billion master plan by Daniel Libeskind would transform 56 acres of land adjacent to the Han River in central Seoul. The new district would contain a wealth of modern office space, shopping malls, hotels, and 4,700 residential units. 

Triple One, image via Renzo Piano

At the centre of this hub is the 112-storey Triple One. Rising to 620 metres, the Renzo Piano-designed conical building would become one of the world's tallest towers. Scattered around Triple One, a multitude of other skyscrapers designed by starchitects take on dramatic appearances.

Dancing Dragon Towers, Dream Hub, image via Adrian Smith + Gordon Gill

Adrian Smith + Gordon Gill's two Dancing Dragon Towers include cuts in their scaly facades which create living spaces. The development is not to be confused with Libeskind's Dancing Towers, a trio of twisting 41-storey towers that were also planned for the complex. Another 46-storey office building by Libeskind, The Harmony Tower, takes inspiration from Korean paper lanterns. 

The Cloud, image via MVRDV

MVRDV's The Cloud sees two residential towers connected by protruding boxes which house the amenity spaces. Bjarke Ingels Group's Cross # Towers channel that idea and build upon it with two above-ground connections. Situated above the horizontal bands, rooftop gardens provide views in all directions. The theme of skybridges continues with JAHN's Pentominium Tower, offering up luxury residences and four-storey parks perched high above the streets below. 

Cross # Towers, image via Bjarke Ingels Group

Block H by Kohn Pedersen Fox Associates proposes a five-star hotel and luxury condominiums with a casino in its basement. The 385-metre tower, like its neighbours, would incorporate rooftop gardens atop the tower's winged sections. A cantilevered swimming pool hangs over the edge. 

Block H, image via Kohn Pedersen Fox Associates

The Diagonal Tower by Skidmore, Owings & Merrill would rise 343 metres and feature column-free office space. The square floor plan rotates twice, creating a series of unique triangular expressions that are clad in high-quality glazing. 

Project R6, image via REX

Project R6 by REX houses small residential units intended for short-term living. Its cantilevered volumes allow for the creation of terraces and communal areas. A number of other buildings house varied uses, from the retail and office complex The Blade by French architect Dominique Perrault, to the C1-20 Tower by Tange Associates which features event space, educational facilities, and a programmable digital facade. 

C1-20 Tower, image via Tange Associates

All in all, 18 world-famous architects collaborated on the project, which had been scheduled for completion in 2016. The Yongsan Development Corporation's default on a major loan repayment threw the project into limbo and it looks increasingly improbable that this vision will ever see the light of day. A scaled-down version may still be possible, and a complex featuring even half as many towers as originally proposed would remain an impressive feat. 

Dream Hub, image via Yongsan IBD - Dream Hub

What do you think of Dream Hub? Do you have a favourite tower? Let us know in the comments below.