Two women in bikinis are on a beach, just metres apart. One is reading a book and browning her skin, the other wears a climbing harness and carries a 30-metre length of rope. Neither thinks the other is out of place - it's just a typical day on Thailand's Railay Peninsula. High above the two women, I am spread-eagled against a cliff face. My index fingers are jammed inside two tiny holes in the rock and my feet are on a ledge as thin as a politician's promise. I am somehow supposed to pull myself up the cliff like this. Who's smarter, I wonder: me or the woman with the book? I fall, answering the question. The other woman leans back on her harness and casually saves my life. 'Try again,' Soley, the climbing instructor calls, but I ignore him, content to hang here and admire some of the finest coastal scenery on Earth. North of the city of Krabi, Railay's beaches are among the most stunning in the world. Around them, limestone towers and cliffs rise like giant pillars of petrified salt, each topped with an afro of forest. The ink-blue Andaman Sea stretches to an island-studded horizon. Yet this is a rare Andaman destination that must coax its visitors into the sea. 'Dive now, climb later', signs implore. Railay's water may be warm but its rock is hot. First discovered by climbers in the late 1980s, Railay has become one of the planet's most famous rock addresses. Its cliffs are laced with more than 700 bolted routes and it supports six climbing stores. Climb or recline? Beaches or bolts? These are Railay's quandaries. Though it's been years since I stepped into a harness, for three days in Railay I'll be stuck to the rocks like a barnacle. Soley, on the other hand, has been climbing here for 14 years. As partnerships go, I'm Jerry Lewis to his Dean Martin. We begin on Diamond Cave North Face, one of Railay's easiest rock walls, so dotted this morning with climbers in board shorts and bikinis it resembles a vertical beach. As we eye the routes, a group of British climbers wanders up behind us. 'That's the climb we made the mistake of starting on yesterday,' one says, tracing a line up the cliff with his hand. It's the same mistake I'm about to make. Part-way up the wall I feel a discomfort familiar to climbers. My forearms have become as hard as, well, rock and my left knee is doing a jittery Elvis-type dance, an embarrassing twitch known among the climbing community as 'sewing-machine leg'. I hang on the rope for a while and wonder why I didn't stay on the beach. In the afternoon, though my climbing is as raw as my fingertips, Soley instructs me to lead a route, which means climbing virtually unprotected, attaching the rope to the bolts as I climb. If a route leader slips, they fall twice as far as would their charges, who are roped in. By some miracle of mind over complaining muscle, that doesn't happen. I live to climb another day, though first I have some beach time owing to me. Railay's sunny side is effectively a tale of four beaches. Railay East and Tonsai are the peninsula's poor beach cousins, the former a muddy, mangrove slop at low tide, deluged by sea at high tide. The latter drains to a rocky sea bed on the waning tide. Railay West is a spectacular strip of long, curving sand, though it also has the most longtail boat traffic, giving it the atmosphere of a speedway track at times. The pick of the beaches is Phra Nang, set beside a holy cave and coated in flour-soft sand. With this beauty comes popularity and shades of Phuket-like industry: inflatable toys, beach massages, buckets of beer and longtail-boat snack bars nosed up to the shore. Visitors with money and skin to burn can stay beside Phra Nang Beach at Rayavadee, where safari-style bungalows cost up to US$4,500 a night, though most beachgoers are drawn to the string of resorts along Railay West. Climbers and backpackers have commandeered laid-back Tonsai where, just a few steps from restaurants and bars, limestone cliffs overarch the beach. Hanging from them are stalactites and climbers, the latter looking remarkably agile until compared with the dusky langur monkeys playing in the forests above. Tonsai is a place where climbers come to drop out from the world, staying for extended periods, working on their technique and their dreadlocks - something like Goa in a harness and climbing shoes. One San Franciscan woman I climb beside tells me she has packed her belly-dancing outfit. Later, I see her juggling bowling pins on the beach. The next morning, I'm joined on One Two Three Wall by Yuki and Komiko. Yuki is a seasoned climber but it's Komiko's first climb. It's sobering when she turns out to be my equal on the rock. One Two Three Wall is one of Railay's easiest rock faces. With about 60 routes, it's also the most popular wall on the peninsula. Ropes hang from its bolts like hair and local guides scurry barefoot up its jagged edges. It's not until midway through the day that my confidence truly kicks in. Leading a climb that funnels into a cave, I finally think my way to the top (apart from when I crack my head on a stalactite) rather than just muscle up in a panic. There are squeals of 'Your other left!' directed at another hapless climber and I realise I'm not doing so badly after all. My body aches but my mind is soothed. That evening, in an effort to placate a few sore spots, I treat myself to a Thai massage, though it's debatable whether having somebody play Twister with your body eases more pain than it causes. For my final day of climbing, Soley has promised to take me to Thaiwand Wall, the incisor of rock that dominates Railay West Beach. Reaching it is half the adventure, scrambling through a dark cave to emerge at an opening high above Railay West and a view fit for the gods. Newly-weds Kevin and Kirsten are my climbing companions today and as we abseil 30 metres from the cave to the base of the wall, Kevin is already unimpressed. Reluctantly, he inches down the cliff like a slug, curses issuing faster than the rope. It comes as no surprise when, halfway through the first climb, he begins hugging the rock as though it's his mother, pleading to come down. Kirsten, meanwhile, has taken to the rock like lichen. She climbs with a grin, she falls with a grin and she whoops with joy as she abseils off the wall at the end of each climb. When she's out of earshot, Kevin talks me through his failed climb. 'I wasn't scared about falling,' he assures me weakly. I know who wears the climbing shoes in that couple. For the final time I grope my way up Thaiwand Wall, following like breadcrumbs the chalk spots of previous climbers, feeling as comfortable now as the sunbathers below me on the beach. I find a hold like a handle and turn to admire the view across the peninsula. This alone makes every muscle ache worthwhile. Getting there: Dragonair ( www.dragonair.com ) flies from Hong Kong to Phuket, from where Railay is two hours by ferry. Railay offers a range of accommodation from rented tents to the luxury bungalows of Rayavadee ( www.rayavadee.com ). For more hotels and climbing information see www.railay.com .