Abstract: A tension leg platform consisting of a platform deck (3) supported by a buoyancy structure (1), a bottom anchoring structure (2) and tension elements (4) extending between the buoyancy structure (1) and the bottom anchoring structure (2). The buoyancy structure (1) comprises a hollow, annular, substantially cylindrical wall forming a can-shaped body having a vertical axis and being fully open at the upper and lower ends, the height as well as the diameter of said body being substantially larger than the thickness of the annular wall in plan view, said wall consisting of closely adjacent, closed, substantially cylindrical, upright concrete cells (5, 7), of which at most half are extended to the platform deck (3) to form supporting shafts (7') therefor.