Altarnun, named in the doomsday book of 1086 as Penpont but takes its present name from the 6th century Church of Saint Nonna where St Nonnas alter was originally preserved. Several legends of the early Celtic saints describe how they used to carry the portable stone altar with them. The modern spelling of Altarnun is a corruption of the earlier Altarnon. Nonna was the mother of Saint David and is the patron Saint of Pelynt near Looe.

Many people will come to Altarnun to see the church, known as The Cathedral of the Moor because of its size. It is mostly 15th century, but it holds a beautifully carved Norman font with strange faces at the corners and also a wealth of 16th and 17th-century woodwork, as well as the intricately crafted 15th-century screen. In the churchyard is a Celtic cross thought to be at least 6th century. A significant restoration of the church was undertaken in 1867.

There is also a Non-Conformist connection at Altarnun; John Wesley came here to preach in 1744. The house where he stayed at Trewint was restored in 1950 and opened to the public. Wesley Cottage continues to provide a unique visitor experience set in an 18th Century Cottage and Chapel which is thought to be the smallest Methodist preaching place in the world.

More famous names from the past are linked to the parish. Sculptor Nevil Northey Burnard was born here in 1818, and he left behind a carved head of John Wesley over the door of the former Methodist chapel in Rose Hill. The Wesley carving was crafted when Burnard was just 16 years old, installed 1836. Several more of his works can be seen adorning gravestones in the churchyard.  He became famous when he sculpted the head of Edward vii, then Prince of Wales & Duke of Cornwall. 

Still within the parish boundaries at Bolventor, is Jamaica Inn and used by Daphne du Maurier as the setting for her 1936 novel of the same name. Du Maurier visited the Old Rectory at Altarnun and featured it in Jamaica Inn as the home of the notorious vicar, Francis Davey.