The present invention aims to provide an antenna tower structure (10) comprising an essentially vertical elongated tower body (20) with an internal installation shaft (30) provided therein. The tower is arranged to house a radio base station (40) in the installation shaft in the vicinity of one or more associated antennas (50) at the top of the tower body. The tower body is comprised of two or more modular segments (S1, S2 . . . ). There is also provided a modular antenna tower segment (S1, S2 . . . ), a method for assembly of a modular antenna tower, a method for assembly of a modular antenna tower, and a method for assembly of a modular antenna tower.