The map ac_twintowers is one of the ACR official map.
This map have two towers and a ground level central field. The towers work as the team bases during team play. However, this map isn't symmetric, only the central field has any significant symmetry. The two bases are different and, the ladder of the eastern tower down to the wall of the central part while the ladder of the western tower on down to the top of the stairs.
This map is part of a family of similar maps made for AC.
The Cube map twintowers have a similar name but isn't related to these maps.