Expedition to the London Stone, Allhallows (4 miles); and Grain Coastal Park (5 miles)

The Walk: This is a walk in two parts. Part one makes an expedition to the London Stone, an obelisk in the Thames Estuary off the shore of the Isle of Grain, near the village of Allhallows. The return route is via the eponymous Wetherspoons pub in the Haven Holiday Park, and the Victorian Slough Fort, if open. Part Two relocates to the nearby Grain Coastal Park at Grain village, and walks the length of the path South to the Cockleshell Pier, then North West along the beach to the fence of the MoD Firing Range. Highlights are the Grain Gun Tower out on the mudflats and the WW2 Dragons' Teeth coastal defences.

The London Stone

Dragons' Teeth, Grain beach

Route

NB1 The map shows my route, with various diversions and excursions which you may not wish to follow precisely. You can download the Google map info, as a KML/KMZ file, then convert to GPX using a site like GPS Visualiser.

NB2 These walks can only be completed on a falling or low tide, and you may get your feet wet. See 'Challenges' below.

Part 1: Allhallows circuit including the London Stone

The walk to the London Stone is shown in BLUE. Park in Allhallows (see 'Logistics'), and take the path from the end of Avery Way, out across the marshes to the sea wall (a grassy embankment), from which the obelisk should be clearly visible ahead. Follow the embankment around into the Yantlet Creek. When you reach a memorial stone, descend carefully to your left (see 'Challenges') and find a shallow crossing to ford (you will probably get your feet wet!).

The Yantlet. I crossed at the end of the rocky spur

This North Western tip of the Isle of Grain between the Yantlet Creek and the MOD Firing Range is open access land. Walk along the mainly sandy beach to reach the stony 'island' on which the obelisk stands, surrounded by mud and shingle. When I did it, the best approach was to carry on along the sandy beach to reach a dry shingle 'causeway' which avoided the mud.

There was a shingle 'bridge' to the London Stone at the far end

Retrace your steps back across Yantlet Creek. You can either return to your car the way you came, or complete the circular route by following the ECP along the embankment, entering the holiday park and walking along the seafront lawn in front of the holiday homes, until you can cut up through 'Adventureland' to the Wetherspoons.

The ECP goes along the lawn in front of the holiday homes

Having done whatever in Wetherspoons, make your way up to Slough Fort to see if it is open (charge). Otherwise, walk to the main gate of the Park and return to your car.

Open day at Slough Fort

Part 2: Grain Coastal Park

From the Park car park, head south along the obvious sea wall (PURPLE route). The path ends at the Cockleshell Beach, where there is a pier, bedecked with signs forbidding further progress along the beach. Return the way you came. (Optionally, you can follow paths through the woods to explore the overgrown remains of the Grain Fort.)

The sea wall at Grain Coastal Park (Gun Tower and Sheerness on the horizon)

Having returned to the car park, head along the coast in the opposite direction (RED route). Having crossed the greensward, you reach a beach which is blocked by piles of concrete Dragons' Teeth. A footpath is shown on OS maps, but there is no signposting on the ground. It is possible with care, at low-ish tide, to follow a ribbon of shingle avoiding the Dragons Teeth, to soon reach a more open beach (though still littered with concrete debris). Plod along this beach and reach an in-tact array of Dragons' Teeth, and just beyond, the fence demarking the Firing Range. Return the way you came.

Jumble of Dragons' Teeth at the start of the beach walk

Why do it?

Previously, I walked the English Coast Path (ECP) along the Grain/Hoo Coast from Grain to St Mary's Bay. The present walk fills in two gaps I was not able to do at that time.

The first (Part 1) is to make an excursion from the ECP to walk to the London Stone, located across Yantlet Creek on the foreshore at the Western end of the Isle of Grain. The grade II listed granite obelisk is a boundary stone marking the eastern limit of the City of London’s centuries-old jurisdiction over the River Thames. It is directly opposite the Crowe Stone, on the Essex coast, forming a boundary line across the river – over four miles wide at this point. The City erected markers such as these in several locations, and the Mayor and his entourage would visit them annually with great ceremony in order to remind the locals of the City's control of tariffs, navigation and fishing rights etc. (There is another such marker on the Medway on this walk, at Upnor.) The Crowe Stone dates back to at least the eighteenth century (the current one dates from 1836). The London Stone on the opposite side of the Estuary was something of an afterthought, being erected in 1856, only one year before the City passed custodianship of its rights to the Thames Conservancy.

The London Stone

The beach leading to the London Stone is a surprisingly exotic looking sandy affair. Inland can be seen the various LNG storage tanks, which were viewed from the other side on this walk around Stoke Marshes.

LNG Storage Tanks

The Yantlet Creek was originally a more significant stream. It joined with the Coalmouth Creek to the South thus making a channel linking the Thames to the Medway, and making Grain an Island, rather like the River Wantsum cut off the Isle of Thanet. The channel was a favoured route for small ships, as a shortcut between the two rivers.

The Yantlet

I returned via the Haven Holiday Park, mainly because it has a Wetherspoons named after the London Stone. The pub is open to passers-by, you don't have to be a guest, but you can't access the Park by car. The Park is a rather reduced version of the original which was planned between the wars to be a major seaside destination for Londoners. Another relic of that time is the incongruously large Pilot Inn, currently empty and undergoing refurbishment. The Second World War scotched that development, and the branch line railway to the village was closed in 1961.

Wetherspoons, London Stone Pub

As luck would have it, Slough Fort on the perimeter of, and overlooking, the Park was having an open day and it was well worth looking around. It was initially built between 1861 and 1867, as one of a ring of forts to defend against a possible French attack on Chatham Dockyard. Specifically, the fort would deter any landing on the Grain/Hoo coast with the intention of crossing the peninsula to attack the dockyards overland. The fort was progressively upgraded to incorporate new longer range guns, and served as part of the coastal and air defences in both the First and Second World Wars. After WW2, the Fort and surrounding land down to the shore was sold back to private developers for their holiday park project (see above). Thus, the holiday park was built on the 'killing field' between the Fort and the shore, where any invader attempting a landing would have been gunned down.

Slough Fort gun ranged over the Holiday Park

The second gap-filler (Part 2) is to walk the coastal path at the Grain Coastal Park, which comprises the strip of land looking across the Medway Estuary to Sheerness. According to signing, the path along the sea wall heading South from the car park forms an isolated 'cul-de-sac' of the ECP, although it is not shown on the official National Trail website. Inland, there are views across the Grain power complex with its two power stations (SSE Thermal and Combined Heat and Power), transformers and pylons, and beyond the end of the path at the Cockleshell Pier can be seen the cranes of London Thamesport.

Grain electrical power generation complex

Some 500m offshore on the mud flats is the ugly yet impressive bulk of the Grain Gun Tower, first built 1848-1853 to defend the mouth of the Medway, in conjunction with the Garrison Point Fort, visible on the other bank at Sheerness (see this walk). As with Slough Fort, it was progressively updated - in the Second World War, a gun directing tower was added. The fort is connected to the mainland by a causeway, the remnants of which are uncovered at low tide. It is possible to walk out along this, although it is very muddy in parts, and will flood rapidly as the tide comes in.

Grain Gun Tower, with causeway walkable at low tide

In the woods overlooking the park are the remains of a dummy gun battery, and the Grain Fort, though the latter is largely overgrown.

Overgrown remains of Grain Fort

Heading North West from the car park, it is possible to walk along the beach to the boundary fence of the former Grain Firing Range. The beach is littered with the Grade II listed remains of WW2 Dragons' Teeth, shaped concrete blocks on a regular grid designed to impede vehicles of any invading force. At high tide, the rising sea covers the easier path along the waterline at the start of the path. Although it is marked on OS maps as a footpath, it is not signed, as I suspect the authorities wish to discourage explorers. The Firing Range remains out of bounds, presumably due to the risks from unexploded ordnance, which is a shame because it would be great to walk along the beach to join up directly with the London Stone and Yantlet Creek.

Grain Marshes Firing Range boundary fence

Logistics:

Part 1: In Allhallows, I parked streetside in one of the few spaces outside the Pilot Inn (now being renovated). Otherwise, park considerately elsewhere on the roadside, being careful not to obstruct driveways etc. (Note the car park at the end of Avery Way is exclusively for residents of the adjacent caravan park.)

Roadside parking outside Pilot Inn

Part 2: I then drove round to Grain Coastal Park (c15 minutes) and parked in the large free car park overlooking the shore at the end of the road through Grain village.

Distance:

Allhallows: From the Pilot Inn to the London Stone: 1.5 miles one way. Full circuit via Haven Holiday Park: 4.5 miles

Grain Coastal Park: Sea wall to barrier at the Cockleshell Pier: 2 miles one way. Beach to Firing Range perimeter: 0.5 miles one way. So both walks together, out and return: 5 miles

Challenges:

On the Allhallows walk:

The walk to the London Stone can only be safely done at low tide. As the tide rises, it will cover the beach around the Stone (and the lower portion of the obelisk itself), and raise the level in the Yantlet Creek. Check tide tables (Sheerness is the nearest tide station), and start the walk around 2 hours before low tide, and allow sufficient time to return across the Yantlet, unless you are prepared to get rather wet.

Take care descending to the Yantlet

The approaches to the Yantlet Creek are down a rough grass embankment, then a rocky and muddy foreshore. Pick your way with care to avoid tripping or slipping. Especially, avoid the very slippery and steep muddy banks down by the stream. When I did the walk, I had to chose the crossing point carefully: the shallowest parts seem to be at the more downstream end, and even then I got my feet wet.

Where I forded the Yantlet

You approach the obelisk along a pleasant sandy beach. The stone itself is on a stony 'island'. When I did the walk, I went across a rather muddy stretch which I don't recommend, but I returned on the far side, where there was a dry shingle 'causeway'. Take care, the rocks around the obelisk are slippery.

I headed directly across this muddy patch: better to head to shingle crossing on the right

On the Grain Coastal Walk:,

It is possible at low tide to walk out along the causeway to the Grain Gun Tower. I was too late to do this, and much of the causeway seemed covered in rather slippery mud. On the return walk about an hour later, the tide had come in and the Tower was an island. Make sure to allow sufficient time around low tide, and maybe wear wellies?

Approach to Grain Gun Tower at high tide (compare previous photo)

The North Western beach is liable to flooding at high tide. This might force you either to get your feet wet, or to scramble over the Dragons' Teeth boulder field, which requires extra care. The whole beach is littered with concrete debris from the old defences, so proceed with care to avoid tripping or slipping.

Rough going on the Grain beach

MoD Grain Marshes Live Firing Range

The two walks Parts 1 and 2 are separated by the MoD Grain Marshes Live Firing Range. Irritatingly, this is out of bounds. I think it is no longer active for live firing, but there must still be a risk of UXB. Hopefully, in the future, a walk along the beach could be cleared of UXB to allow the public access as a tidal alternative to the current inland route of the ECP (see this walk).