At the Bookham Commons, the purple emperor season peaks in the 2nd week of July. From lunchtime to early evening, the males can be seen at the Mark Oak and Hill Farm 'Master Trees'. © Matthew Oates/NT

White admiral is common at the Bookham Commons, so much so that in most years the rare black admiral colour form, shown here, occurs. See them in shadier places. © Matthew Oates/NT

Silver-washed fritillaries are abundant in July where they are seen in Bookham’s woods. Look for them feeding on the nectar of brambles and thistles. The males produce a scent on their wings that attract females. © Matthew Oates/NT

Deep in the Purple Empire…

Great Bookham CommonEnter one of the best woods in England for the rare and elusive purple emperor. Each afternoon the males gather at two special trees and put on amazing territorial displays. You’ll also enjoy plenty of other butterflies and many birds in this Site of Special Scientific Interest.

Start: Close to Bookham Station, OS Landranger 197:TQ130565

Getting there and facilities By train: Bookham (regular service) By bus: 622 from Epsom, or 479 from Epsom, Guildford and Leatherhead to Bookham train station By bike: Surrey route 3 By car: M25 (J9) then A243, A24 & A246. After 2 miles turn R onto High St, then

L onto Church Rd. Various car parks incl. near Bookham station. Pubs in Bookham. NT restaurant/tea room at Polesden Lacey (NT).

Points of interest

'Master Trees' In the 1970s, two purple emperor 'Master Trees’ were discovered at Bookham

Commons. They are special trees – usually oaks and the tallest trees in a wood – where males fight to protect their territory, and females come to mate. The males have even been known to take wood pigeons that invade their patch! You should see at least one or two purple emperors in an hour. In the morning, you may see them on the ground.

Bookham Commons A superbly rich area of broad-leaved woodland. It is one of the best-recorded

insect sites in Britain with over 1,500 species of beetles. The Trust manages the woods carefully by keeping rides open for butterflies and, as far as possible, fallen trees in situ. Insects benefit greatly from dead wood and they, in turn, support birds.

Other Wildlife Fantastic birdlife with woodpeckers, hawfinches and nightingales. In scrubby areas

look for southern marsh orchids and, in ponds, great-crested newts.

As a charity, independent of government, the National Trust relies on the generosity of its supporters to continue caring for our countryside and wildlife, so that everyone can enjoy the beauty of the outdoors for generations to come.

Find out more at www.nationaltrust.org.uk

National Trust places nearby

Polesden Lacey, Box Hill, Ranmore Common, Denbies Hillside, Headley Heath

Distance, terrain and accessibility

1½ miles return. Moderate slopes. Rides can be very muddy in wet weather.

Route and directions

1. Leave Tunnel Car Park and head north west. Search for purple emperors down on the lower, southern slopes of the commons. Your best chance of seeing them is late morning:10.30 to 11.30 to be precise!

2. Follow the main path (Common Road) towards and past the houses: all the open sunny rides in this part of the Bookhams may reveal male purple emperors (don’t ask, but rotting fruit and even dog poo are popular!). Look out for the closed wings of the male that resemble a shark’s fin.

3. Turn right onto Hollows Path that leads past the lakes. They are worth exploring and tend to be good for white admiral, silver-washed fritillary and dragonflies.

4. Turn left before the wood edge and go up Broadway. This leads to the Mark Oak 'Master Tree' on the left just before the ride junction at the top. Purple emperors fly high in the canopy and can be difficult to spot. Patience is needed!

5. Turn left and westwards to follow High Point Path.

6. Spend an hour at the Hill Farm territory and at the second 'Master Tree' (a hornbeam) located just south of the farm.

7. Continue to the houses at the Isle of Wight and retrace your path to the car park and station.