Channel change

Richard lives in a Martello tower and in his garden is an old double-decker bus, a boat that took part in the Dunkirk evacuation and, he’s been told, the bodies of two Napoleonic soldiers. In the next field are the gateposts and a few other remnants of the only concentration camp to be built on British soil.

My son and I came across him at the start of a glorious bike ride around Alderney. One moment we were edging up to the tower to see what it was and the next we were having a chat on the top deck of the bus. It had been the venue of a party the night before, binoculars lay on the seats from birdwatching and it’s also used as a field classroom for the primary school. Richard bought it on eBay (shipping was just that – £800 from Lancashire via Poole) for his son to play in. The same goes for the boat.

All that remains of the Lager Sylt, the concentration camp, are the concrete gateposts, a stairway, a short tunnel and three sentry posts. More than 400 men died here during their incarceration, many by strangulation. Alderney is equally familiar with war and peace.

The site of the camp is next to the airport. We diverted off the track for a fine vantage point towards Les Etacs, a dramatic islet that is home to two per cent of Britain’s gannets. From this distance each bird – there are 6,000 of them in peak season – floated like a single feather and the guano looked like icing on a rock cake.

Around the corner we gazed at Fort Clonque way below us, cunningly built on a rocky outcrop. This is one of 13 formidable forts built in Victorian times to counter a perceived threat from the French who were mustering at Cherbourg, eight miles away.

The only time the forts were used was about a century later – by the occupying German army which built concrete gun emplacements and look-out posts on top of the forts in some cases. Cycling across the causeway to the fort was a great novelty but today it’s a holiday let (one of the German gun emplacements is now a bedroom) so we couldn’t continue over the drawbridge. Other fortifications are used by young people for bunker parties while the look-out tower next to our B&B, which was the local headquarters for the Luftwaffe, is now a mobile phone mast.

We soon reached the next fort, Tourgis. In contrast to Clonque it is completely unrestored – and all the more atmospheric for it. We padded cautiously around the derelict interior, staggered at the scale and strength of the construction which was akin to a factory or workhouse. Baths and toilets are still in situ. Equally, prodigious is the half mile-long breakwater at Braye, also built as part of the Victorian fortification.

Most of the northern coast of Alderney consists of fabulous beaches, all of them practically deserted even on the August bank holiday weekend of our visit. There’s no beach infrastructure and all parking is free. If you want refreshment you just have to hope that the island’s only ice cream van is on its way.

As we approached the sweeping arc of sand that is Saye Bay we heard the sounds of gunfire from Fort Albert above and a brass band playing in a field and watched a group – the only one on the beach – having a jolly wheelbarrow race.

Over a headland was our favourite beach, Corblets Bay, which has the added interest of rocks ideal for a quick scramble.

The causeway to Fort Houmet Herbé – the next fortification on our tour – has all but disintegrated and is accessible only by foot at low tide. We were in luck and made the crossing, clambering up from the rocks and through the giant door for a nose around. On a charred iron fireplace you can still make out the initials VR.

Round the corner is the fort on the Isle de Raz – or Rat Island, as it’s also known – which is connected via a concrete causeway.

In common with all the forts on Alderney, this one is low-level and has a Moorish look of a castle with its towers chopped off. A giant red buoy reminded us of the Alderney stones, some of which we’d found earlier on our circuit. They are 11 three-tonne round boulders, each five feet in diameter and formed of compacted clay and soil. Through erosion they reveal materials and objects relevant to their location such as seeds, ropes, gloves and old tools.

The shadows of a golden summer’s day were lengthening as we checked out a children’s beach art competition. It was being judged by BBC TV wildlife presenter Miranda Krestovnikoff, a regular visitor to the island, on Longis Bay surreally just yards from a mighty German anti-tank wall. The man at the Alderney Museum later told me how the bodies of some PoWs were kicked into the concrete as it was being cast.

We just had time to nip back for a close-up look at a German fire direction post which, perched precariously on the edge of a quarry. It had intrigued me all the way around the eastern tip of the island. The most sinister and menacing of all the concrete carbuncles, it’s reminiscent of the helmet of a suit of armour or an art deco cinema. The locals call it the Odeon.

As I stood beside the bunker suddenly, out of nowhere, I heard a clanking chugging noise and a Thomas the Tank Engine-style train pulling 1950s London Underground carriages crawled along the quarry below me, gradually slowing down as it approached the engine shed.

The line was originally built to transport stone to the harbour and now carries tourists. In the distance was the Mannez lighthouse.

From the malign, to the benign to the bizarre, Alderney is an island of many moods.

Factfile

Getting there: Fly from Leeds Bradford via either Southampton or Jersey. See aurigny.com for Alderney connections.

General information plus map: visitalderney.com.

Recommended accommodation: Farm Court B&B. farmcourt-alderney.co.uk.

Bike hire: Either Cycle and Surf (01481 822286 and cycleandsurf.co.uk) or Top Gear (01481 822000 or 824672).