The bumblebee is back. Thank the Army

Walk Of The Month: Pembrokeshire - An MoD firing range on the Welsh coast proves a perfect host to wildlife. Mark Rowe finds an ally in the battle for conservation

The tale of the bumblebee and the soldier sounds like something from Aesop's Fables. Yet, collaboration between the Army and environmentalists is the theme of this month's walk, which explores the glorious scenery of southern Pembrokeshire.

The entire walk goes through the Castlemartin training area, land owned by the Ministry of Defence and used intensively by troops for live firing and tank manoeuvres. Intuitively, you might think that a military training area – and one that is used day and night for much of the year – would have little to offer wildlife. The reverse is true: the fact that the public is kept at bay, coupled with military land not being intensively farmed, makes places such as Castlemartin hugely important for our embattled wildlife.

Castlemartin also hogs an outstanding stretch of coastline that includes dramatic limestone features, such as arches, sea stacks and blowholes. For many years, you would have to take the Army's word for this, as the MoD has traditionally been less than welcoming to walkers – The IoS ran a successful campaign 11 years ago to prod the Army into improving access.

A further sign of this openness – warily granted in some quarters – comes in the form of a newly opened bumblebee walk that cuts across Castlemartin and enables walkers to steer clear of roads that they have traditionally been required to follow when live firing is taking place. The route, beginning in the village of Bosherston and heading to Merrion camp and beyond, is being planted with bumblebee-friendly plants, such as red clover, knapweed, bird's foot trefoil and common vetch, all of which flower from the end of this month through to August.

The shrill carder bee, one of the rarest in the UK, is expected to be one of the chief beneficiaries. "It's not necessarily what people would expect," said Dr Pippa Rayner, conservation officer for the Bumblebee Conservation Trust. "The MoD has proved very co-operative. Without the MoD you wouldn't have this fantastic landscape."

The bumblebee friendly leg of the walk is where we kick off, heading from the church in Bosherston towards St Twynells, picking up the waymarkers for the bumblebee walk (a tank on a green background) that threads its way between Army training camps (red flags will fly when training is going on) and around military roads and field edges to reach Merrion Camp. Along the way the scenery is attractive heathland interspersed with hedgerows, and perhaps the odd bee, as well as the many butterflies, will make an appearance.

It is at this point that you realise there are limits to the Army's willingness for public access. The route drills due south along a road that divides the east and west ranges, but the western side of the range, west of the Stack Rocks road, is permanently off-limits to the public. A few times a year, rangers are allowed to take guided parties into the zone, though you must first sign a blood chit, absolving the Army of responsibility should you tread on unexploded ordnance. It's no surprise that Castlemartin is described as the "missing tooth" in the Pembrokeshire coast path by access campaigners.

The scenery is pleasant enough either side of the path at this stage, with the curious spectacle of tanks conducting exercises against a backdrop of tractors dropping off feed for sheep and wind-pummelled trees. Lonely St Martin's Church is worth a brief diversion along the way, its wrought-iron gates were paid for by the West German army, which trained here during the Cold War.

The scenery really takes off once you reach Stack Rocks car park. From here you have a glorious three-mile walk due east of staggering geological beauty. Start by gazing from the wooden viewing point down at the spectacular arch known as the Green Bridge of Wales, then wander east to Stack Rocks and the thrilling standalone precipices chock-full of razorbills and guillemots. Look west and you'll see the island of Skomer and St Ann's Head, along with the towering chimneys of the Milford Haven oil refinery. The headline furrows in and out of the Bristol Channel; this is easy, exhilarating walking. Below, lonely bays and huge landslides are exposed at low tide. The military training area is adjacent, on the north side of the track, and posted warnings remind you every few hundred yards not to wander inland.

Eventually, you'll come to a second car park, below which, huddled, seemingly chiselled into the cliff face as it tumbles to the sea, is the tiny St Govan's Chapel, reached by a flight of steps. It's thought to date back to the sixth century; be sure to look out for the tiny cell up to your left as you enter. Legend has it that a sip of the rainwater that accumulates in the hollows in the chapel cures rheumatism and eye problems. It's a serene spot, and given its location amid a sea of Army paraphernalia, a slightly surreal one.

Compact Facts

How to get there

Mark Rowe stayed at 3 The Glen, Saundersfoot, as a guest of Coastal Cottages of Pembrokeshire (01437 765765; coastalcottages.co.uk). The property, which sleeps up to eight, is available for holiday rental from £708 per week.

Further information

Visit Pembrokeshire (0844 888 5115; visitpembrokeshire).

Bumblebee Conservation Trust (bumblebee conservation.org.uk).

Directions

OS Map: OL 36 South Pembrokeshire

Distance: 10 miles

Time: four hours

The bumblebee-friendly leg of this walk is not yet on the OS map, but is clearly waymarked from the iron gate at the first fork on the road from Bosherston and St Twynnells (962949). On passing Merrion Camp, turn left, due south, for 1.6 miles to Stack Rocks. Head east for 3.5 miles to Newton Down car park. Walk north through the car park, following the lane for 1.5 miles back to Bosherton. The bumblebee stretch can be walked at any time, even during military firing; but the rest of the route can be undertaken only when there is no training, usually at weekends.

Check with the local range office on 01646 662495/662225.