Swinley Forest

Where it sits. Swinley Forest covers roughly 2,600 acres of pine plantation and heath on the sandy ground between Bracknell, Ascot and Bagshot in Berkshire, about thirty miles west of central London. It belongs to the Crown Estate and forms the southern lobe of what was once the Royal Forest of Windsor, separated from Windsor Great Park by a few miles of suburb and the M3 corridor. The main visitor entrance is at The Look Out Discovery Centre on Nine Mile Ride, on the southern edge of Bracknell.

The ground beneath it. This is Bagshot Sand country: acidic, free-draining, poor for farming and superb for conifers, which is why the Crown planted it commercially with Scots and Corsican pine. Between and beneath the plantations survive fragments of lowland heath, one of the rarest habitats in Europe and rarer in Britain than tropical rainforest is globally. The heaths here form part of the Thames Basin Heaths Special Protection Area, designated for three ground-nesting birds — nightjar, woodlark and Dartford warbler — which is why dogs are asked to stay on paths in the breeding season from March to September and why parts of the forest are fenced or restricted at times. A major wildfire in 2011 burned several hundred acres and reshaped whole compartments; the regenerating heather and young pine on those areas are visibly different from the dense mature plantation around them.

On screen. Swinley Forest was one of the principal woodland locations for Harry Potter and the Deathly Hallows: Part 1, the film in which Harry, Ron and Hermione spend months on the run, moving camp from wilderness to wilderness. Unit filming took place here in June 2009 and again in February 2010, and call sheets from the shoot record forest and lakeside woodland work on Crown Estate ground. Understanding what that means on screen is the interesting part. The film's fugitive sequences were assembled from many places — Berkshire pine plantation, Scottish lochs, Welsh valleys, Yorkshire limestone — and then unified with visual effects. Mountains, rivers, cliffs and skies were added around the trees, so a stand of commercial Corsican pine within earshot of the M3 becomes a remote wilderness with Highland ridges behind it. The forest floor and the trunks are real Berkshire; almost everything on the horizon is not. No set was built and nothing was left behind, so there is no marked spot to find, which is exactly the point: what makes Swinley usable to a film crew is that any patch of it looks like any other.

What you actually do here. Swinley is best known today as a mountain-biking centre. The Crown Estate built and maintains waymarked blue, red and black trails from the Swinley Bike Hub next to The Look Out, with hire bikes, coaching and a café, and the trails are genuinely well made — bermed, rooty, fast, and rideable year-round because the sand drains almost immediately after rain. Walkers and runners have miles of gravel forest road and single track; the Look Out has an interactive science centre aimed squarely at children and a large play area. Horse riding is permitted on designated tracks by permit. Caesar's Camp, an Iron Age hillfort on the ridge to the south, is the one archaeological feature worth seeking out, though it lies on Ministry of Defence land and access can be restricted. Swinley Forest Golf Club, a Harry Colt heathland course laid out in 1909 on the eastern side, is private and shares only its name with the public woodland.

Getting there and timing. Bracknell station, half an hour from London Waterloo, is about two miles from The Look Out; there is a large pay-and-display car park at the centre, and smaller Crown Estate car parks at Swinley Road and Rapley Lake. The forest is open daily and free to walk in; you pay for parking and for bike hire. It is a working plantation, so trails and rides close for felling and extraction at short notice — check the Crown Estate's notices before a long drive. Autumn and winter are quiet and atmospheric, with mist sitting in the rides; spring brings the heath birds; summer weekends are busy with riders. Underfoot conditions are sandy and firm, but the terrain is undulating and there is no fully surfaced accessible circuit beyond the immediate area around The Look Out.