ILKLEY, an urban district in the West Riding of Yorkshire, England, 16 m. N.W. from Leeds on the L.M.S. and L.N.E. rail ways, in Middle Wharfedale and extending to Ilkley moor. Pop. , 9,721. It is a health resort and has several hydropathic establishments. The remains of Bolton abbey lie in the Wharfe valley 5 m. above Ilkley. Camden was the first authority to recog nize Ilkley as a Roman site, and associated it with Olicana. Little excavation work and few discoveries were made until the 19th century, when Roman objects were found. A systematic excava tion of the fort began in July 1919. Much of the site has been destroyed since Roman times. From the structure of the rampart and from finds from deep levels, it is inferred that the fort was established before the end of the 1st century and that a civil settlement sprang up around it. Occupation continued, with breaks, into the 4th century, but the exact date of the final with drawal of Roman garrisons is still in dispute.