Today's award goes to the architecture firm BNKR Arquitectura in Mexico City. The Daily Mail reports:
Architects have designed an incredible 65-storey 'earth-scraper' which plunges 300 metres [984 feet] below ground.
The stunning upside down pyramid in the middle of Mexico City is designed to get around height limits on new buildings in the capital.
The subterranean building will have 10 storeys each for homes, shops and a museum, as well as 35 storeys for offices.
A glass floor covers the massive 240m x 240m hole in the city's main square to filter in natural light from the world above.
The design has been crowned with a Mexican flag.
Esteban Suarez, from architecture firm BNKR Arquitectura, said the building would also house a new cultural centre.
He said: 'New infrastructure, office, retail and living space are required in the city but no empty plots are available.
'Federal and local laws prohibit demolishing historic buildings and even if this was so, height regulations limit new structures to eight storeys.
'The city's historic centre is in desperate need of a makeover but we have nowhere to put it, this means the only way to go is down.'
There's more at the link, including many more (and much larger) pictures.
The only problem I can foresee is the small one of survival! Mexico City is sitting right smack bang in the middle of a highly active earthquake zone. A major earthquake in 1985 killed at least 10,000 residents and caused massive damage to the city. Knowing that, would you really want to be living several hundred feet underground when the next major quake hits? What are the odds your apartment would become your tomb?