Spa Lane begins at the open space (public square?)where Hopesprings, Pallant Street, and Water Street meet. It curves back towards the hill of the Tump, and offers one of only three access routes, at Mithering Heights, to the old (Latatian?) road that climbs the Tump in a rough spiral. Being called a "spa" is interesting in this context: the old acqueduct that at one time brought fresh water into the city is discussed more fully elsewhere but there is circumstantial evidence to suggest that it was routed through, rather than around, the Tump. A spa is a naturally occuring water spring, often hot owing to geothermal activity and carrying a lot of dissolved mineral salts. Could a spa of this nature once have existed here? And like Edinburgh Castle, is the Tump built on all that remains of a long-extinct volcano, whose last residual signs of subterranean activity were a hot spring? Indeed, might the spa be still there and still visited by those who have faith in the healing properties of hot water? (In which case, it cannot be doing too much business in modern Ankh-Morpork).