So … You have to get to Weston Super Mare at the crack of dawn, you get herded into a crowded open boat in which several people will be sick if the sea is anything other than millpond-flat. You then take over an hour fighting currents to get to this rock in the middle of the Bristol Channel where you are abandoned for the rest of the day. When the boat returns on the evening tide to take you off again, several strapping crewmen have stand waist-deep in the water, struggling against vicious currents and the pitching of the ship to hold the gangplank in place and haul you back aboard as fast as possible to make your escape.

It's brilliant!

The only problem with trips to Steep Holm is that many of them have to be called off. The tides and currents make landing on its tiny pebble beach hard enough at the best of times. In rough weather, there's no chance. Which is how come your correspondent has made several attempts to get out there down the years but only succeeded a fortnight ago.

But it is well worth the trouble and expense, because this is without doubt one of the very best outings on offer around these parts. It’s a fabulous adventure, and you have to love being on this uninhabited, unspoiled island, all alone there in the midst of one of the most populated regions in Europe.

Steep Holm is that enormous rock sticking out of the Bristol Channel. It's clearly visible from the coast all along here, looking like the back of an enormous whale sticking out of the water. What the view from Bristol, Avonmouth, Clevedon, Weston or Burnham-on-Sea doesn’t tell you is that that's just the narrow end you can see. It's actually quite long. There's 50 acres of it in all.

The island was bought in the 1970s by the Kenneth Allsop Memorial Trust as a tribute to the conservationist, broadcaster and author who died in 1973 (he never visited the place). The Trust is a registered charity and the island is now protected as a nature reserve and Site of Special Scientific Interest. The Trust, mostly through the good offices of 20 or so committed volunteers, plus many more supporters, maintain the island and its visitor facilities.

In its time, Steep Holm had a Roman signal station (some archaeological fragments have been found), a medieval priory (currently being excavated) as well as being a base for fishermen, the very occasional farmer and a fair few smugglers. Indeed, as the boat approaches the island, you almost feel as though you’re in an Enid Blyton story.

Once you’re on the island and have climbed the path to the top you find the most visible remains of human activity are from the 1860s and 1940s. Back in Victorian times, amid a long-forgotten scare that the French might try and invade us, a series of defences – generally known as 'Palmerston Forts' - were built along the coast. Steep Holm got a series of gun positions as well as a barracks for a small permanent garrison of artillerymen. The stone-built gun emplacements (the technical term is 'barbettes', fortification fans) are still there, as are the guns, massive seven-ton Victorian muzzle-loading cannon long since removed from their mountings but way too heavy for anyone to ever have bothered taking them away.

There are more recent fortifications from another invasion scare. Hastily-built gun and searchlight positions from 1940-41. It probably doesn’t float your boat, but personally I was thrilled to encounter a Bofors 40mm anti-aircraft gun, even if it is rusting away and covered in seagull crap.

Ah yes, the seagulls. The advice here is that if you're visiting in spring/early summer, wear a hat. The gulls don’t take kindly to intruders going anywhere near their chicks, so you will be dive-bombed or (in my case) flapped around the head by a juvenile who'd not yet learned to fly properly yet. Don’t knock the gulls; the wildlife is why the place is so well preserved, after all. Though you gotta sympathise with the lady who wrote in the visitors' book: "I HATE gulls. I could have written this in my own blood."

Aside from gulls, there are also cormorants nesting on the rocks on one side, as well as some very rich vegetation, including several medicinal and herbal plants which are rare on the mainland. Lots of poisonous ones, too.

One of the most remarkable things about the place is the fantastic work that the Trust's volunteers have done down the years, especially when you consider that everything has had to be brought from the mainland, gotten onto the beach and then lugged up to the top by hand. They've converted the Victorian barracks into a visitor centre complete with a huge, airy café (tea, coffee, cake, snacks and booze) and a couple of exhibitions on the island's history, wildlife and archaeological finds. There's also a very nice area outside with fabulous views of the Channel coast where you can eat your picnic and argue about where Burnham-on-Sea is.

Because of the difficulty in landing people – and, rather more importantly, getting them off again – there are no trips out there in winter, and the last one this season is on October 1. The ticket price is not exactly cheap, especially if you're taking a family, but it beats Alton Towers into a cocked hat any day and nobody is grasping at profits here; it's all in a good cause.

# Remaining trips to Steep Holm this season (2008) are on August 2, 4, 17, 20, 31; September 2, 15, 17, 28; Oct 1. Tickets £25 adult/£12.50 age 5-16, no under 5s due to safety regulations. Ffi: 01934 522125, www.steepholm.org