Riddlesdown is an elongated area representing the eastern portion of Purley, which is the north section of the postcode sector. Cutting the postcode sector in half horizontally is Mitchley Avenue, which is just south of Riddlesdown railway station. The western border roughly follows the A22 (Godstone Road), while the northern border trails the railway from Purley to Purley Oaks. The eastern and southern border is less well-defined, as they pass through the green areas of Purley Downs Golf Club as well as Riddlesdown Collegiate Grounds. The railway from Sanderstead to Riddlesdown and Upper Warlingham cuts through the postcode sector vertically, dividing the area into the western built-up area and the greener eastern portion. Riddlesdown does not have a noticeable high street, although there are shops scattered throughout the area, and Purley town centre is in the northwest, just outside the boundaries of the postcode sector.

Purley Hall is located to the west of Riddlesdown, and was built in 1609 by Francis Hyde (the original name of the estate was Hyde Hall). Since then it has gone through many owners – it would later be sold to Francis Hawes, a director of the South Sea Company, by Francis Hyde’s grandson (who was curiously also named Francis, so the house was passed down from Francis to Francis and sold to Francis). When the ‘South Sea Bubble’ burst, it was then sold to his younger brother. The house was vacated during the Second World War and changed hands again during the 60s. The 80s brought a period of restoration, particularly to the garden. Today, the house remains in private hands.

Francis Hawes owned Purley Hall for a short duration during the 18th century, but went bankrupt due to his involvement in the South Sea Company. The South Sea Company had obtained one of the most lucrative trade monopolies in the world, and as such felt secure in reissuing stocks; the public meanwhile was captivated and bought said stocks as the price rose. Eventually, the bubble would collapse and many involved would go bankrupt. Francis Hawes would have his estate sold off to cover his debts.

Purley Golf Course has a history dating to the 1890s, when golf first started to be played on site (it was then a farm, with the local golfers persuading him to allow them to play alongside the sheep). The club would be established in 1894, with a wooden clubhouse being built. The famous JH Taylor, who designed many other golf courses in South London, helped design an 18-hole course at the turn of the 20th century, although the course today has been radically altered since then.

The Old Coulsdon Hash House Harriers is based in the postcode sector, and runs every week, alternating between Mondays and Sundays. Hashing originated in the Federated Malay States (today Malaysia) in the state of Selangor; and describes an activity where a group goes running, while stopping at pubs on route (essentially a pub run instead of crawl). The OCH3 (as it is so abbreviated) has been organising runs since 1984, and still do today (a run costs £1.50, including a bag of crisps and a drink). The first run is free, so there’s nothing to lose!

Residents claim that there is overdevelopment in the area, including a (now cancelled) skyscraper in the area, which would have been built on derelict land. However, there are also debates that these housing projects need to be built – the debate continues on, with ramifications for the council’s future.

Some of the smaller bungalows are in the process of being converted into flats, being able to build up to 3-storeys. There’s also been some controversy regarding new proposals for development in the area in recent years. More than 120 locals objected to plans for a house in Riddlesdown Road to be replaced with a five-storey block of 21 flats. While the proposal was originally rejected in 2019, it was approved following an appeal in 2021. Vita Group is also developing a complex consisting of a family home and 4 boutique apartments located at walking distance from Riddlesdown Train Station. The Riddlesdown Residents’ Association has also been very active in communicating with the council for more clarity regarding development proposals. In 2019, they encouraged locals to object to a development on Green Belt Land in the area that would build between 350 and 780 new homes.