Heritage Open Day: The Mother Church of the City of Lancaster, Lancaster Priory is a Grade 1 listed building, located on a site which has seen Christian worship since Saxon times. It is of huge historical and archaeological importance. Offering a unique and interesting interior, there is much to see inside the building. Lancaster Priory is a church where the voices of all are regularly lifted in prayer and praise focused on God in worship. Our annual Priory Festival in September, most of which is free to attend, celebrates our Patron Saint, the Blessed Virgin Mary. These events take place amongst the ongoing worshipping life of the Priory, showcased in Festival Sundays and Evensongs.