The ruins of St. Oswald's Priory in the City of Gloucester is an interesting place to visit, for me again on a hunt for a geocache.
St. Oswald's Priory was founded by Lady Aethelflaed of Mercia, daughter of Alfred the Great, around 900. The Priory Church, initially dedicated to St. Peter, was constructed from recycled Roman stones. At this time it was a bold and unusual move to build a church as there were frequent Viking raids.
Best viewed with the magnify button above the pic.