The date of the Oratory is open to question, but it is somewhere between 5th and 7th century.
The Oratory was abandoned because of the encroaching sands. Centuries later it was dug up again but there was so much damage due to visitors that it was buried again.
For further information: www.st-piran.com/main.htm
The church and the cross are about 100 yards to the right of the plaque below. They are quite close to the fence.
To get to the Oratory, got to the point marked on the map and park. Go through the gate at the start of the footpath and then look behind you to your right and you will see a map to guide you. Take the right path for about 300 yards, it is a bit overgrown but it will then widen out. You will see two white markers on the ground, go between them but keep to the left and a white marker should guide you most of the way. After about ten minutes brisk walk you will see a cross on the horizon on top of a hill. The Oratory is about 100 yards in front of the cross but to the right. It is about a 15 minute walk. There are many people walking dogs across the dunes and any local will know where the sites.