12thc. circular aisled nave with unlighted gallery and central ribbed dome on a lighted drum. To this is attached a rectangular two-bay aisled chancel, originally of the 13thc. The present appearance owes much to Salvin's restoration of 1841: particularly the chancel, the W doorway, the gallery capitals and the entire drum and dome of the nave, which replaced a 15thc. bell-storey. The church is built of ashlar.

The site was granted by Abbot Reinald of Ramsey (1114-30) to the members of the Fraternity of the Holy Sepulchre, an organisation about which nothing else is known. Such authentic work as remains suggests a date at the end of Reinalds' abbacy.

Very little of this sculpture is authentic work of the 12thc., probably only the nave arcade capitals and the capitals of the aisle vault responds (though not the corbels of the diagonal ribs). Perhaps the main interest of the building for the historian of sculpture is in the range of pseudo-Romanesque forms used in Salvin's restoration and enthusiastically approved by the Cambridge Camden Society.