Arch sites are structures that are built in the shape of an arch. They are typically used to span a large area, such as a river or valley, and are often used as part of a bridge or other structure. The term 'arch sites' can refer to the actual arch structure itself, or to the entire site where the arch is located. The crossword solutions for the term 'arch sites' are 'insteps' (7 letters), 'FEET' (4 letters), and 'SHOES' (5 letters). These words allude to the idea of an arch, with insteps being the curved part of the foot, FEET being the base of the arch, and SHOES being the covering of the arch.