St. Adamnan's Church, Lonan, Medieval church in Baldrine, Isle of Man.

St Adamnan's Church, known in Manx as Keeill ny-Traie, "the chapel by the shore", is the former parish church of Lonan on the Isle of Man. It stands in open farmland on the eastern coast between Groudle Glen and Baldrine. Its eastern, oldest part has been restored, while the rest is ruinous but well tended.

The original building dates from 1190 when King Reginald of the Isle of Man granted the land to St Bees Priory in Cumbria. This gift linked the remote island community to a monastery on the English mainland.

The churchyard holds Celtic crosses, the oldest dating to the 5th century AD, evidence of an early keeill on the site. The Manx name Keeill ny-Traie means "the chapel by the shore", recalling the coastal setting of the original foundation. The Friends of St Adamnan's, formed in 1968, keep the old church in repair as a working church and historical site.

The church stands in open farmland between Groudle Glen and Baldrine, reached by minor roads with no village centre nearby. The eastern part is restored and the rest is a well-tended ruin, so expect uneven ground and grass underfoot. The Friends of St Adamnan's, formed in 1968, keep the site in repair; contact them about access before setting out.

The eastern section was restored while other parts were intentionally kept in a maintained ruinous state. This mix of restoration and preserved decay tells a story of how the building changed and endured over time.