The church of St Mary is a fine Gothic structure of the 13th century with five naves and a lofty spire.
The façade is fine, and the interior, divided into three naves by columns, with galleries over the aisles, has fortunately not been restored; the vaulting of the crypt has, however, been covered with modern stucco.
Of Halstead is Little Maplestead, where the church is the latest in date of the four churches with round naves extant in England, being perhaps of 12th-century foundation, but showing early Decorated work in the main.
Oblong, having a single row of columns dividing the length into two naves and terminating to the west in a semicircular apse.
It is true that at all times churches have been put to secular uses; in periods of unrest, as among the Nestorian Christians now, they were sometimes built to serve at need as fortresses; their towers were used for beacons, their naves for meetings on secular affairs.