Kantiang Bay at sunset

South of Long Beach, Koh Lanta gets hillier and quieter. Klong Nin is long and open; Kantiang Bay is closed in by green hills, with forest running almost down to the sand; beyond it, smaller coves are quieter still. These are the beaches for a couples session or a proposal at sunset, when the sun goes down over open sea with very little between you and the horizon.

The hills give the bay a frame the long northern beaches do not have: green on both sides, the curve of the sand, the sea straight ahead. Start about an hour before the sun touches the water — the light worth having comes in the second half of that hour and the first minutes after — and the photographer can be on the sand as another evening walker before you arrive. In the dry season the sea is flat enough to stand in for a frame, and the wet sand at the water's edge doubles the sky.

Some of these southern bays have rocks in the water, so a family with small children usually stays up the coast at Klong Dao or Long Beach. From about May to October the monsoon makes the west coast rough and the red flags go up — a red flag means no swimming, literally. Lanta has no airport — the nearest is Krabi — and the island is reached by road with a car-ferry crossing, so keep the session away from the day you travel.