Exploring the marshes around High Halstow

This rectangular walk follows a quiet route from the nature reserve of Northward Hill via the tiny settlement of St Mary Hoo, partly along the long-distance Saxon Shore Way.

The spur of marsh and low sand-and-clay hills between the Thames and Medway estuaries has been settled since the Bronze Age. The Romans made the first attempts to build sea defences and drain the marshes, and later it became a Saxon ‘hundred’. At the eastern end of Hoo lies the Isle of Grain, a futuristic expanse of power installations and container terminals. The rest of Hoo is mainly rural, populated by wild birds and grazing stock.

For centuries, the Hoo peninsula was a lonely and inhospitable place, its waterlogged soils too saline for agriculture, the marshes infested with mosquitoes. In the 19th century, convict hulks were anchored just offshore, and their desperate, shackled cargoes were vividly conjured by Charles Dickens in the opening scenes of Great Expectations (1860). But the marshes also provided a haven for wildlife, which suffered when they were drained in the 20th century.

This patchwork of woods, grassland and hawthorn scrub at Northward Hill Nature Reserve (RSPB) attracts many unusual birds, including avocets, egrets and nightingales. The reserve’s most distinctive species is the grey heron – more than 180 pairs breed here each year. Walking trails criss-cross the reserve, with dramatic vantage points at intervals. Spring is a good time to visit, when the herons are nesting and the woods are carpeted in bluebells. But you can spot interesting birds at any time of year, especially in winter when the trees are bare.

Take the fenced footpath beside house No. 15 at the far end of Longfield Avenue. Turn left and left again through a kissing gate, then walk up the right edge of the field ahead. Bear right through the hedgeline and take another kissing gate into arable fields.

Following the Saxon Shore Way, go ahead across the fields until you reach Decoy Hill Road. Turn briefly right, then left round a bend. Pick up the Saxon Shore Way ahead, across a field, and follow this to reach a footpath crossroads.

Turn left off the Saxon Shore Way and take a grassy track between hedges. Cross a stile and keep going, skirting to the right of a tree-lined hollow. At the field margin, cross a stile, then another a few paces to your left. Follow the fenced path downhill past brambles (watch out for rabbit holes).

At the bottom you will meet Decoy Hill Road again. Continue along the winding lane as far as a farm, Swigshole, where the road ends. Take the track ahead via a stile beside a locked gate. In a few paces meet a footpath junction, one bearing left across the marshes.

Turn right through a gate along the fence-line, following orange markers. Continue eastwards for about 0.75 miles (1.2km), parallel to the estuary. When you meet another path crossing at right-angles, turn right again, following waymarkers over several fields divided by gates (use the stiles if they’re closed). Keep ahead when the land starts to rise more steeply. Make for a thin copse, leaving it on your right over another stile. Just past the end of the copse the footpath merges with a track leading from your right.

Bear left uphill, then right through a waymarked gateway past two barns. Ahead in the distance you will see a tall industrial chimney and closer at hand, slightly to your right, the square tower of St Mary Hoo church. Zig-zag past Ross Farm, bearing left at a handful of village cottages to visit the church.

Retracing your steps a few paces to the first bend, now follow the track straight ahead across open fields towards Newlands Farm, taking steps to the right of the path to avoid wandering into its grounds. Walk through a bank of ornamental trees, past a duck pond, and continue ahead on the field track to reach the footpath crossroads again. Retrace your steps via the Saxon Shore Way to your starting point.