London: the step-by-step guide Michael Leapman relishes rhododendrons in royal Richmond Park

Richmond Park has London's finest show of azaleas and rhododendrons and this is a pivotal weekend to relish them: many of the rhododendrons are coming into bloom and the azaleas are not yet finished. They form a spectacular climax to this walk around the wildest of London's royal parks, with its magnificent trees and roaming deer.

The area's royal connection dates from the 12th century, when Henry I had a manor at Sheen, north of the park. Three hundred years later, Henry VII built a palace here and called it Richmond because he was the Earl of Richmond in Yorkshire. The park itself was enclosed in the 1630s by Charles I who used it for hunting deer.

From the Kingston Gate car park go back to the mini-roundabout at the junction of two park drives. First cross the road and then a tarmac path and turn right on a dirt path between oak trees, with the park's western wall (first put up in 1637) on your left and the north-south road on your right.

Keep on this winding and undulating path for about 15 minutes until it forks by a large oak tree. Take the right-hand fork and shortly afterwards fork right again by another oak with a prominent dead branch. This grassy path climbs to the road that leads to Ham Gate.

Crossing the road, keep straight ahead up the steepish hill. At the top, pass to the left of a large hollow stump on to a gravelled path that affords fine views across woodlands on the left.

You are walking beneath oak and horse chestnut trees at first but ahead you reach an avenue of hornbeams that give this path its name of Hornbeam Walk. At a fork, with a mound ahead, keep right to skirt the mound and stay near the road, soon joining a wider gravel path.

The gardens of Pembroke Lodge are now ahead, behind railings. Enter them by an unobtrusive gate, marked "No cycles". At the metalled path keep left to walk past beds of pieris and a few rhododendrons, giving a taste of what will come later. Ahead, behind colourful flower-beds, is the 18th- century lodge, itself now housing an indoor and outdoor cafe. Keep to the left of it and, beyond the outdoor tables, turn sharp right on a brick path beneath a flowing cherry.

Turn left on the wider tarmac path and then keep to the broad drive, with azaleas on your right. Leave the lodge grounds through a pedestrian gate on the right of a cattle grid, cross the road and keep roughly ahead on a path that passes to the left of a blasted oak and crosses the horse ride, towards the corner of Sidmouth Wood.

The slight rise on your left is known as Henry VIII's Mound, because it is where the king, staying at Richmond in 1536, is said to have stood to await the pre-arranged launch of a rocket from the Tower of London, as a signal that his second queen Anne Boleyn had duly been executed. The view east towards the City is still uninterrupted and is protected by law.

Walk around Sidmouth Wood, keeping the fence on your right. There are masses of rhododendrons on the edge of the wood but a fortnight ago they looked some weeks from flowering. As you round the corner of the wood, the Penn Ponds come into distant view below.

Fork left on the downhill path that goes towards the water and eventually runs between the ponds, former gravel pits flooded in the 18th century. You will see swans and ducks and, if you are lucky, a heron or two. On a hill on the left, partly hidden by trees, is the White Lodge, built in 1729 and now the home of the Royal Ballet School.

Past the ponds, keep right on the main path, then go diagonally across the car park on your right to an information board. Cross the tarmac drive signposted "Isabella", directly behind the board, and keep ahead on a broad, grassy path between horse chestnut trees, climbing gently uphill towards a wood.

After crossing the horse ride, take the right-hand of three paths (the one with the most grass on it). When you get to a wire fence around a wood, keep it on your right until you reach the green ornamental gates of the Isabella Plantation, home of the dazzling azaleas and rhododendrons.

At the gate is a map and a notice telling you about the seasonal highlights. There are many ways around the garden: just go where your eyes draw you. In general, the rhododendrons are mostly on the outer paths and the azaleas, brooms and heathers near the streams that run along the centre. Make sure your route includes Peg's Pond at the far end and Thomson's Pond near the east side of the plantation.

Returning to the gate you entered, turn right and then fork left on a rutted grass path across scrubland. Cross the horse ride and the road and then walk alongside the horse ride until you cross the next road near Ladderstile Gate. Here take one of several paths that run between the road on your right and another section of 17th-century wall on your left.

I feared I might end the walk without seeing the famous deer but scores of them were congregating close to the road at this point, oblivious of the traffic and people, although signs around the park warn that they can start to get snappy in May. Soon the car park comes into view ahead.