Some items were moved here from the old church, including the 13th-century font, two bells from the 14th and 15th century, and a reliquary thought to hold the remains of St Nidan.

"[4] The 19th-century clergyman and antiquarian Harry Longueville Jones said that it had been built in a "debased barbarous style, showing neither architectural science nor taste".

[2] The architect was John Welch, who also designed St Ffinan's Church, Llanffinan, in central Anglesey, which was built in 1841.

[7] Like its predecessor, it is dedicated to Nidan, a 7th-century Welsh saint who was the confessor of the monastery at Penmon, on the eastern tip of Anglesey.

[1] St Nidan's is built mainly from red gritstone rubble, dressed with sandstone, with buttresses at the corners; the roof, which is made from slate, has stone copings with a cross at the east end.

[2] The quadrant-shaped organ room and vestry are built into the eastern external angles of the chancel and transepts, one on each side of the church.

[2] The gallery at the west end of the nave, supported by octagonal columns, is reached from the entrance porch; it has its pews set at an angle.

The chancel window depicts "Faith, Hope and Charity", by Heaton, Butler and Bayne (1877); it is dedicated to the 5th Lord Boston who died in 1897.

[2][4] A sandstone chest with a glass front was moved here from the old church; local tradition maintains that it holds the relics of St Nidan.

[10] In 1906, a survey of church plate within the Bangor diocese recorded that St Nidan's had a silver chalice and alms dish.

"[4] Writing in 1846, the clergyman and antiquarian Harry Longueville Jones condemned the treatment of the old church, which he said was "one of the largest and most important in the island of Anglesey", given its architecture, contents and traditions.

[5] He said that the new church had been built "in a debased barbarous style, showing neither architectural science nor taste, and without any example or analogy amongst the ecclesiastical edifices of any age, except the present.