Beneath the Catholic cathedral is a huge crypt designed by Edwin Lutyens for an immense neo-Romanesque cathedral that was never built. The original design would have been roughly three times bigger than the Houses of Parliament and featured a dome bigger than that of St Peter's in Rome. The crypt is occasionally used for concerts; there is also a Treasury of religious items and a small exhibition on Lutyens' plans, which faltered due to a lack of funds after WWII.