Chester Racecourse, known as the Roodee, is according to official records the oldest racecourse still in use in England. Horse racing at Chester dates back to the early sixteenth century. It is also thought to be the smallest racecourse of significance in England at 1 mile and 1 furlong (1.8 km) long.

The 65-acre (260,000 m2) racecourse lies on the banks of the River Dee. The site was once a harbour during the Roman settlement of the city during the Dark Ages, but was closed as the river silted up thus making navigation impossible. Towards the centre of the in field is a raised mound which is decorated by a small cross known as a "rood". It is from this that the race course derives the name "Roodee"; Roodee is a corruption of "Rood Eye", meaning "The Island of the Cross".

More Info: en.wikipedia.org