Phi Phi Leh is the southern of the two main islands and has an even more spectacular sheer cliff scenery.
It's a rugged, jagged rock a 30-minute boat ride to the south of Ko Phi Phi Don. It also has an especially pretty beach, Maya Bay.
It was on Maya Bay that scenes from The Beach were controversially shot in 1998, catapulting the island to international prominence, and as a result, over a decade later, tourists continue to descend here both for day trips and overnight camping stays.
The beach is indeed quite pretty, but you'll probably find it a bit smaller than you imagined it to be, and while this is a national park (only overnight stayers need pay the admission) there is a simple shack at one end selling prepackaged snacks and drinks.
Once you've walked the length of the beach and tried out the brief jungle trail that goes through to the short-cut entrance, there isn't actually that much to do here other than swim and lay around. There's no coral to speak of (though you'll see fish) and while there is another beach you can swim to, you need to be on the full day-trip (or camping stay) to have adequate time.
You can visit Maya Bay in a number of ways. You can just go hire your own longtail or speedboat, or go jump on one of the many half-day or full-day snorkelling boat trips which will visit here along with a few other spots. Which to choose depends on your budget, but in hiring your own longtail you can visit early in the morning, meaning you can enjoy the beach with fewer people -- at other times, especially into the afternoon, it can get quite crowded.
The camping may sound tempting, but we were not that convinced of its value. Despite the added expense, if you're looking for that real Crusoe experience, we'd say a camping trip to Bamboo Island is a better option.
Half-day trips to Ko Phi Phi Leh go for 250-300/400 baht per person with full-day trips costing around double. Expect a further hike in high season. These need not be in a longtail and generally the bigger the boat, the cheaper the price and the larger the number of passengers.
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