Old Church of St. John the Baptist

Nave with transepts and chancel, and a porch beneath a tower on the N side. Local rubble masonry brought to courses, with traces of external render. A tomb recess in the S of the chancel projects boldly externally, and is in ashlar masonry. The chancel arch wall and the S transept have been rebuilt partly in brickwork. There is a modern door to the S of the nave.

The E window is large but now lacks all tracery. Windows N and S of the chancel are possibly Tudor, but restored with modern brick segmental arches. Some good details survive in the N transept: at the N side three cinquefoil-headed lights under a Tudor arch; at the E side three tall cinquefoil-headed lights of equal height, also Tudor. In the S transept, rebuilt in the C17/18, there are round-headed windows at E and W and two roundels in the S gable.

The entrance at N faces toward Slebech Park and the presumed site of the commandery. Tudor-arched entrance doorway, 4-centred, beneath a relieving arch. Two carved shields in the spandrels and shields also at the terminations of the label mould. In the first storey above is a lancet window with a small carved shield above it. In the second storey there are square-headed apertures to the N and E. Twin belfry lights to N and S, single to E and W, all Tudor-arched.

Nave, transepts and long chancel at one level, with a wide chancel arch, a large rise at the sanctuary and a large tomb-recess (the effigies from which were removed to the new church), a late insertion in the S wall of the chancel. The chancel arch probably C14. The arch to the N transept is 4-centred, perhaps C15, with a late gothic enriched moulding at the impost. The arch to the S transept is modern. Step up to the porch beneath the tower, with an adjacent water stoup. The tower base is given a typical Pembrokeshire pointed barrel vault. Laws and Owen's description (1907) refers to the Barlow vault beneath the chancel.

The N transept was the Picton family chapel or pew, although the principal Philipps family memorials are in St Mary's in Haverfordwest. An altar stood at the E, with a small piscina and with a trefoil-headed aumbry cut into the E pier of the transept arch. The stairs to the tower commence from this transept.

The S transept which was the Barlow family chapel or pew is rebuilt in stone patched in brickwork. There is a fireplace.