Sculptor David Černý and architect Tomáš Císař from the studio Black n' Arch have designed a 135m ( 450ft)-tall tower for Prague shaped like an upended shipwreck with an observation deck at the top.

Top Tower comprises a conventional high-rise tower with a base section that partially acts as a pedestal for the accompanying sculpture, which takes the form of a sunken ship's skeleton covered in seaweed. The sculpture is not just a visual element, but also a structural one.

"The boat is structurally connected to the building," says Tomáš Císař from studio Black n' Arch. "One cannot stand, or even exist, without the other. Thus the boat is not a mere addition, but rather a fundamental element both intellectually and technically."

The tower will contain rental housing, offices and space for a cultural centre.

The public will be able to access the viewing deck via a ski lift. Once at the top, they'll have 360-degree views of Prague, with landmarks such as Prague Castle and the National Theatre visible. As Císař explains, there will also be a publicly accessible roof garden.

"The boat becomes a connecting living element between the square, roof garden and viewing points at the highest level," he said. "It comprises a vertical public space, is publicly accessible via the viewing elevator and staircase which link individual levels or terraces, which in future will be used as outdoor galleries and gardens."

The building will also have commercial units and underground private and public parking spaces. The scope of the 2 billion Kč (US$86m, €78m, £68m) project will include the revitalisation of an adjacent pedestrian zone.

Project developer Trigema expects construction of Top Tower to begin in 2021 and take three years to complete.