Epsom and Ewell (yōˈəl) [key], borough and district (1991 pop. 66,000), Surrey, SE England. Epsom salts were first prepared in 1618 from the mineral waters there. Epsom was a popular spa in the 17th and 18th cent. It is also famous for horse racing at Epsom Downs, where the Derby and the Oaks are run. Epsom College, a public school, was founded in 1853.