[3] The mausoleum is designed in Neoclassical style, and constructed in ashlar stone with lead roofs and set on a plinth.

It contains a nave, tomb chambers to the north and south acting as transepts, and a mausoleum at the east end.

The top stage consists of an octagonal drum containing eight louvred openings, and this is surmounted by a dome with a cross.

[1] Inside the west entrance is a porch, with a doorway on the south side, and steps leading up to a gallery to the north.

At the east end of the nave is a screen in Ionic style with a dentil cornice containing boards painted with biblical texts.

In the south chamber is a mid 19th-century memorial to the Dukes of Newcastle, carved by William Grinsell Nicholl.