The Great North Wood was a natural oak forest that covered the Sydenham Ridge and the southern reaches of the River Effra and its tributaries. It is a major part of the history of Croydon. The most notable tree, called Vicar's Oak, marked the boundary of four ancient parishes; Lambeth, Camberwell, Croydon and Bromley. John Aubrey referred to this "ancient remarkable tree" in the past tense as early as 1718, but according to JB Wilson, the Vicar's Oak survived until 1825. The earliest surviving mention of the wood dates from assize records in 1272, and it was known to be owned by the Whitehorse family during the reign of King Edward III. When Oliver Cromwell seized it from the Archbishop of Canterbury it was measured to cover, but held only 9,200 oaken pollards. At this time it was known to stretch as far as Streatham from Croydon. Much timber was taken from the woodlands for use in the Royal Dockyard at Deptford as well for charcoal burning and building purposes. Much of the surviving woodlands were cleared and developed as a result of the 1797 Croydon Inclosure Act and sale of the late Lord Thurlow's estates in 1806, although some substantial fragments remain, notably the nature reserves at Dulwich Wood and Sydenham Hill Wood.
Principal open spaces
Apart from smaller green areas such as sports grounds and smaller gardens, and Selsdon Wood, which is National Trust property, the following are the major open spaces in the Borough:
Croydon North
Norwood Grove, Upper Norwood : Mansion, ornamental grounds and parkland, 34.5 acres
South Norwood Country Park, South Norwood : former sewage farm, 125 acres
South Norwood Lake and Grounds, South Norwood : large lake land and green space area, 28 acres
Croydon Central
Lloyd Park , Croydon : founded by Frank Lloyd, 114 acres
Addington Hills, Addington : also named Shirley Hills
Happy Valley Park, Old Coulsdon : countryside area, 252 acres
Farthing Downs, Coulsdon : another countryside area in the borough, notable for its walking trails
Foxley Wood, Purley : An ancient urban woodland with Nature Reserve status noted for its diversity of flora and wildlife encompassed in an urban location featuring a nature trail. The Friends of Foxley in association with London Borough of Croydon manage the woodland.
Water
The River Wandle is also a major tributary of the River Thames, where it stretches to Wandsworth and Putney for 9 miles from its main source in Waddon. It forms a rough western boundary with the London Borough of Sutton, and for part of its length forms the boundary between the London Boroughs of Croydon and Lambeth The main river ends at Waddon with one of its tributaries ending in Selhurst. Another tributary starts in Thornton Heath as the Norbury Brook, becomes the River Graveney and joins the Wandle near Summerstown. Wandle Park is one of 11 parks throughout Greater London chosen to receive money for redevelopment by a public vote. The park received £400,000 towards better footpaths, more lighting, refurbished public toilets and new play areas for children.
Climate
The amount of green spaces in area can affect the climate of that particular area. Croydon has a temperate climate in common with most areas of Great Britain, it is similar to that of Greenwich in Inner London: its is Cfb. Its mean annual temperature of 9.6 °C is similar to that experienced throughout the Weald, and slightly cooler than nearby areas such as the Sussex coast and Central London. Rainfall is considerably below England's average level of 838 mm, and every month is drier overall than the England average.