When Paul Theroux, in his The Happy Isles of Oceania, travelled through the Southern Vanuatu island of Tanna it was to escape the capital's tameness and seemingly the locals' unexpected habit of being 'pleasant and not at all rapacious'. Unperturbed by acts of random goodwill most visitors visit Tanna for another reason - the volcano.

Tanna's volcano, Mount Yasur, is touted as being one of the world's most accessible active volcanoes, enabling the tourist to drive within a five or ten minute walk of its brim. Such a chance is irresistible to extreme armchair travellers such as myself, so I too followed in the steps of the master and hopped on a Vanair Dash 8, landing less than half an hour later at Tanna's delightfully tiny 'international' airport.

I was armed with some inside knowledge. The night before I was due to leave for Tanna I met a pleasant local lawyer called Tom at a kava bar where we discussed my plans. He said to me, 'If there is a big spurt of lava do not be tempted to run away. Instead…,' he looks to the sky and identifies an imaginary lump of molten lava, follows its projection through the air towards his person and does what can only be described as a Michael Jackson moonwalk to the left to indicate the calm avoidance of catastrophe, '…if you run, you will not see it coming.' It was with this strategy in mind that I climbed into the back of a 4WD headed for Mount Yasur. Already in the vehicle were Bob and Claire - an Australian couple who proceeded to look at each other with increasingly nervous smiles for the duration of the drive, somewhat undermining my explorer's resolve.

Despite being only 361 meters high, Yasur makes its presence felt over a surprisingly wide area of Tanna's dense interior. It's not that you see the mount itself, but the fallout of black, powdery, ash that builds up along the sides of the dusty roads like snowdrifts in negative, numerous miles before you reach the base. The ash seems to penetrate, settling on every flat surface and between every bush and tree until finally all life succumbs to the inevitable suffocation in the form of the ash plain.

The ash plain sits like a vast grey mote around the base of Yasur. The 4WD is suddenly spat out on to it and follows threadlike tyre tracks across its lunarscape, charred tree stumps poking out of the grey from time to time, rocks thrown unusually far on one of Yasur's particularly active days. We park next to the remnants of what was once a fruit stall. It is collapsed, blackened, a vast pile of barbecued coconut husks; this is the part of the movie where the psychic member of the expedition team turns to their colleagues and says with notable gravity, 'something destructive has happened here.'

And indeed there does seem something quite ominous about our short ascent to the brim. Our barefoot guide walks slowly in front with his hands behind his back as if leading a funeral procession, the ash is littered everywhere with countless black volcanic rocks of all sizes from pebbles to boulders. A path of precise proportions has been cleared through this fallen debris and the cleared rocks have been constructed into a small tidy wall, sometimes a foot high, lining the path, directing us towards the smoking brim. The absence of colour and the increasing wind give the whole place a lonely dreamlike character, a dream one would probably rather wake from than dwell in.

I pound up the slope behind our guide, Bob and Claire behind me. Having reached the top of the slope and moved along the edge of the brim I look back and see Bob trying to coax Claire on. She has reached the point where she can see over into the mouth of the volcano and has stopped, petrified, in her tracks. She encourages Bob to continue who trudges up and stands beside me. We attempt to look casual, staring at the rupture in the earth's surface, nodding contentedly to each other as if on the top of a gentle hill in the Sussex Downs, admiring the view.

'Yeah,' says Bob, 'there's some pretty serious wind up here.'
'Yeah,' I say, 'it's a bit fresh.' The truth is it's howling, the guide has his head tucked in his shirt and we're all planting our feet firmly into the ash in the hope that it'll stop us being blown over the edge. Lower down Claire seems to be attempting to streamline herself against the wind whilst looking as if she's undertaking some calming mantra.
'It is most unfortunate,' says our guide, 'that the volcano is quite quiet today.' All three of us look at each other and laugh.

The guide informs us that in the local tongue 'Yasur' means 'old man' and that naming is quite apt. The volcano breathes and wheezes slowly like some septuagenarian who smokes forty a-day. Slow, deep, breaths resonate around the bowl of the crater, spitting lava instead of phlegm. Every now and again an almighty chest-clearing cough sees vast clouds of smoke belched out of the firey centre, rumbling beneath our feet.

Later that night at another kava bar, so dark I can't see the faces of the people I'm talking to, I'm asked about my day's activities.

'Oh, I went up Yasur today.'
'Really? How was it?'
'Good, a bit quiet…'

We all nod silently, expertly, tired of watching volcanoes that spit only small jets of lava into the air.