If the aim is to design an “extremely high” building, a very large plant or in any case is needed to be immense in its bottom and narrowed as it goes, as a pyramid...

In any case, the higher the building, the greater must be its plant and increased divorce exist between the building interior and exterior. No matter how high a building is, its views are breathtaking from near the facade ... the rest inside the building is no different from any other with a huge indoor and artificial climate.

... why we propose the typology ring opening a new field of formal exploration, enabling a high tower and therefore, thick at base, but able to leave a gap (hole) inside that provides high spatial complexity to the interior spaces, while plants get enough large to be profitable without losing contact with the outside space.

The most significant buildings in height have been developed from numerous types and variants, but the tower “O” offers something new, it is the only tower in the world hollow. A tower with two facades, one facing the outside enjoying the landscape and nature and a overturned inside, to contemplate the atrium, artificial.