Graduation thesis design of steel observation tower, ground plan is equilateral triangle, which measures 7,7 m in length and 36,4m in height. The basic structure is made of elements with equilateral angle profiles. The columns are assembled of two profiles at an angle 60 ° that enables the connection between horizontal and diagonal on the column. The horizontal member is box profile which prevents large deflections. The staircase is extended in the rim of the triangle, which ends at the top with the observation platform 1 m over the structure. Wind had the biggest influence and is calculated according two standards SIST EN 1991-1-4 and SIST EN 1993-3-1:2007. The last one is relevant for the design. Internal forces are calculated by finite elements software Scia Engineer. The angle profiles are separately checked for buckling, because programe does not consider all parameters to properly calculate buckling. Typical connections are designed. They are mostly pinned. The detailed drawings are collected at the end.