A tower base section, a tower adapter and a wind turbine having the tower base section and the tower adapter are provided. The tower base section includes a tubular side wall and a flange portion. The flange portion has an inner radius and an outer radius and is configured as a T-flange. The tubular side wall is located closer to the outer radius than to the inner radius. The adapter is arranged outside the tubular side wall and includes a bottom surface pressing from above on the flange portion.