Sennen parish church is dedicated to St Sinninus (St Senán), a sixth century Irish saint, but has also been dedicated to St John the Baptist. There has been a church here since at least the 15th century. In 1327 and 1430 the patron of Sennen is described as a female saint Senana. However in later times it has been assumed that Senanus is the patron saint. The identification of this Cornish saint with St Senan of Scattery Island appears to have no foundation.
The present church has a chancel and nave, a south aisle and a north transept. A wall-painting depicting two round embattled towers was uncovered during restoration in 1867. There is also a headless alabaster figure representing the Virgin Mary in the transept. The church has a three-stage battlemented tower housing a ring of three bells.
There are five Cornish crosses in the parish. One is at Escalls and another at Sennen Green. Trevilley cross is one of only two crosses with a crucifixus figure on a cross carved onto the stone (there is a cross on the other side of the head). A cross on the churchyard wall came from a site near the Giant's Stone. A fine cross in the cemetery adjoining the churchyard was found in use as a footbridge near Trevear and moved to the churchyard in 1878. About 1890 it was moved to its present position.
References:Sigmaringen Castle was first mentioned in the year 1077 in the chronicles of Petershausen monastery. The oldest parts of the castle are concealed beneath the alterations made during the 17th and the 19th centuries. The secret of the earliest settlement built on this defendable rock will never be fully revealed: large-scale excavation work would be necessary, which the extensive land development renders impossible. Judging from the many Roman remains unearthed in the area around Sigmaringen, the 12th century keep known as the 'Roman Tower' could be traced back to a Roman predecessor.
The castle remains that have been preserved (gate, great hall and keep) date back to the Staufer period around 1200. The castle remains were integrated into subsequent buildings. The foundations of the castle buildings are to a large extent identical to the surrounding castle wall.
These remains give us a good idea of how the castle might have looked during the 12th century.