Sandown Castle was a Device Fort built at Sandown on the Isle of Wight by Henry VIII in 1545 to protect against the threat of French attack. Constructed from stone with angular bastions, its design was a hybrid of Italian military architectural thinking with traditional English military design. The site was raided by a French force that summer while the fortification was still being constructed. The site suffered from coastal erosion and the castle was demolished in 1631.

Sandown is a seaside resort town and civil parish on the south-east coast of the Isle of Wight, England. The resort of Shanklin and the settlement of Lake are sited just to the south of the town. Sandown has a population of 11,654, according to the 2021 Census; together with Shanklin and Lake, it forms a built-up area of around 25,000 inhabitants. It is the northernmost town of Sandown Bay, with an easily accessible, sandy shoreline with beaches that run continuously from the cliffs at Battery Gardens in the south to Yaverland in the north.