The church of the Holy Cross is located on the south side of Tan-y-groes Street close to motorway (M4) junction 40, and lies in a triangular churchyard used as a cemetery.
It was built in 1827 as a chapel-of-ease by Edward Haycock of Shrewsbury in a pre-archaeoligical Gothic style. A board inside the church reports that it was built with a grant from the 'Society for promoting the Enlargementand Building of Churches and Chapels' and was designed to seat 500 people. The board is signed by William Bruce Knight, minister, and the chapel wardens. The chapel was augmented in 1903 by G.E.Halliday to fit it to become a parish church, and this included the insertion of an ornate rood screen.
The church is of cruciform plan and comprises nave, chancel, south and north transepts, west bellcote and small gabled porch against west end, entrance facing north. It is constructed of rubble stone under slate roofs with sandstone dressings.
Inside, the nave, chancel and transepts are undivided. Interior features include a polygonal pulpit built into the right end of the screen, an octagonal font to west end on an octagonal stem and square plinth, a small polygonal wood panelled pulpit to the north-east on a wider octagonal stone base, and quarry tile flooring to the nave with shields and heraldic emblems.
The church formally closed at the end of 2008, suddenly and unexpectedly for health and safety reasons due to the interior ceiling falling in. It was declared redundant by the Archbishop of Wales the following year after it was deemed too dangerous to continue to worship in and too expensive to repair.

Sources:
Cadw Listing description (extracts).
http://www.st-theodore.org.uk/holy-cross-church/

David Leighton, RCAHMW, 21 January 2015