What to Expect:
Haad Rin on Koh Pha Ngan is the island's most well known beach and it's where you'll find the full moon parties. Haad Rin, at the southeast corner of the island, is really a narrow strip of land that connects the larger island to a smaller land mass below, so there are beaches on both sides. The west facing beach is called Sunset Beach and the east facing beach Sunrise. You can walk from one side to another in just a few minutes. Haad Rin, like most of the beaches in the Samui Archipelago,is rugged and pretty. But, because of the party atmosphere that pervades this beach area, it can get dirty and run down looking at times. If you are not coming to party, there is no reason to stay on Haad Rin. Koh Pha Ngan's other beaches are probably a better choice for you.
The Full Moon Parties:
Like durian fruit, most people have strong feelings one way or another about full moon parties. If you're the type of person who wants to party all night with lots of other young (and not so young) people and aren't bothered by extreme wastedness, sometimes shocking behavior and the general mess created by such events, you will have fun. If you're not into drugs or alcohol and prefer your evening's events to be tranquil, you will hate it. Many observers have noted that full moon parties are getting out of hand and any redeeming qualities they may have possessed have been lost in recent years. Still undecided? Read up on Ko Pha Nga's Full Moon Parties.
Haad Rin's resorts and hostels are almost all three stars or below. The three star properties start around $30 depending on the time of year but can go as high as $90 per night during peak season on party nights. In general, the quality of accommodations isn't great and prices can be surprisingly high, though there are a handful of resorts that do a great job of separating themselves from the hot mess that is the Full Moon Party. There are also some budget "hostels" which are really just bare bones, fan cooled rooms off the beach. You can find these for as little as $10.