igrasaxa consists of two soaring black stone towers, rising above the Orwell river estuary southeast of Ipswich. The two towers are connected by bridges of black stone; the only entrance is at the base of the first tower.

Nigrasaxa was founded by Maximianus Bonisagi, a well-reputed researcher. After his demise, his filius Aelfred Bonisagi inherited leadership of the conventum. Nigrasaxa welcomes Hermetic visitors, and has ample quarters for guests.