The Carrowreagh Quadrant Tower takes its name from the townland in which it stands in Co. Londonderry. Such towers overlooked aerial bombing ranges, offering an elevated site from where crews could observe events and control operations. Officers would provide instant feedback to pilots and bomb aimers during training exercises.
The quadrant tower at Carrowreagh was better equipped than many others. Some would have been nothing more than a single room on elevated stilts. At Carrowreagh close to Magilligan, however, the tower featured an upper room for the Range Control Officers as well as generators and radio and toilet facilities on the lower level.
Since the Second World War, the tower has lost its roof, first-story wooden floor, and the main viewing window which looked north. The still-standing remains are impressive and visible from the roadside at the end of Scotchtown Road.