Many churches across Oxfordshire and Gloucestershire have a circular carved marking with a central hole on their exterior walls. These so-called mass clocks are, in effect, primitive sundials. They were used by the priest to determine the approximate time for calling the congregation to attend Mass.
I recently noticed this example on the church at Fulbrook, Oxfordshire, and have added it to my growing collection of photographs of these fascinating carvings, which you can see on the page for this entry.
This seems to be in such good condition that I wonder if it replaces another one found on the wall nearer to the door of the church.
Here is my gallery of related images held on Flickr.
Click each image here for an enlarged view.