Koh Samui led Thailand's modern spa industry and now offers the widest range of holistic treatments nationwide. Before settling into a beach-hopping loop around the island I book a treatment at Tamarind Springs, an idyllic destination spa where a cavernous herbal sauna — the so-called "dragon's cave" — is set between two arresting boulders.

Chaweng Beach Road offers Samui's most concentrated shopping; where market stalls proffer CDs and designer goods next door to swish boutique arcades, fast-food joints and supermarkets. Local painters operate from street-side studios, replicating masterpieces or producing portraits commissioned by passers-by. After lunch, wander over to Samui Aquarium & Tiger Zoo, where you may be picked for a day's training as a sea-lion trainer.

Day trips 30km west to Ang Thong Marine National Park, the dramatic scenery of which inspired Alex Garland to pen The Beach, can easily be arranged from Samui. The 100km archipelago comprises 42 uninhabited islands, some hosting monitor lizards and pods of dolphins. Scuba dives often take the plunge from the island chain off Ko Yippon, where shallow caves and archways beckon. Hitch on one of the boats over to Koh Pha Ngan, where fire-twirling exhibitionists perform for the party-hearty crowd.

Hop a flight over to Krabi, an area offering abundant scenic beauty, often represented by the spectacular limestone outcrops jutting from the Andaman. Skip the most commercial beach, Ao Nang, and instead take a boat to one of four gorgeous beaches wedged within the limestone cliffs guarding Railay Bay. This breathtaking peninsula hoards 650 rock-climbing routes, and local operators will advise on climbs to suit all levels. In the evening, head over to Tonsai Bay, which runs its own version of the full-moon party.

Sunrise is a good time for spiritual nourishment, so make for Wat Tham Seua, aka "Tiger Cave Temple", a shrine 9km from Krabi Town. A footprint of the Buddha is embedded in a rock located atop the 1272 steps; an exhausting hour-long ascent — but the views are solid gold. Later catch one of the regular two-hour ferries to Koh Phi Phi, lauded an earthly paradise by the first backpacking tourists to visit. Twenty-five short years later, and developers have run roughshod over Ao Ton Sai Bay, although just minutes' away is the quieter, prettier bay of Ao Lo Dalam, with its lovely curve of white sand and clear waters.

Catch a morning boat from Ko Phi Phi to Phuket and escape the possibility of madding crowds by going 10km south-west of Phuket Town to the quiet, yacht-strewn cape of Laem Panwa. Here you'll find Ao Yon, the only beach on the eastern coast sheltered by dual headlands with good year-round swimming.

Set course for the pleasant village feel of Kamala, up Phuket's east coast. This is the site of "Millionaire's Mile", a property hot spot of the rich and famous (including Madonna) in the mountainous headlands. Nearby Rockfish Restaurant is prime for a spot of lunch in the lovely panoramas over secluded Kamala Bay. The beach's northern end can't be developed because of a Muslim cemetery and, during high season, windsurfing, waterskiing, banana boats, fishing and island-hopping trips run daily.