Flanking tower

A flanking tower is a fortified tower that is sited on the outside of a defensive wall or other fortified structure and thus forms a flank.

In High and Late Medieval castles and town walls, flanking towers often had a semi-circular floor plan or a combination of a rectangular inner and semi-circular outer plans.

Corner flanking towers are found, for example, in the fortifications of the Alhambra and at the manor house of Hugenpoet Palace; Wellheim Castle has a square flanking tower.

Semi-circular flanking towers were common in Sasanian architecture.

[1] In church architecture, a flanking tower is a semi-circular or polygonal (for example, octagonal) tower on the outer wall of the church.