A combination of Word War II blitz raids and centuries of urban renewal have wrought havoc on the 14th century medieval structures contained in London's Charterhouse. Some of the remaining medieval construction is detailed in a new book The Charterhouse (Yale, UK£80).
Many of the Tudor-era structures were built over a 14th century Carthusian priory, revealed by bombs in the 1940s. "The central feature of the original monastery was a cloister joining the hermitages of the 24 monks in a square 300ft across. It is neatly depicted on a 15th-century plan of the water supply piped to the cells and monastic church. Yet the location of this church remained hidden until the incendiary bombs fell."