Polygonal masonry

True polygonal masonry is a technique wherein the visible surfaces of the stones are dressed with straight sides or joints, giving the block the appearance of a polygon.

[1] This technique is found throughout the world and sometimes corresponds to the less technical category of Cyclopean masonry.

[2] And others In Italy, polygonal masonry is particularly indicative of the region of Latium, but it occurs also in Etruria, Lucania, Samnium, and Umbria; scholars including Giuseppe Lugli have carried out studies of the technique.

[3][4] Some notable sites that have fortification walls built in this technique include Norba, Signia, Alatri, Boiano, Circeo, Cosa, Alba Fucens, Palestrina, and Terracina.

[5] The Porta Rosa of the ancient city of Velia employs a variant of the technique known as Lesbian masonry.