Haad Rin is a peninsular beach area and town on the southern tip of Koh Phangan, an island in the Gulf of Thailand. Its two main beaches are Sunset Beach (Haad Rin Nai) to the south and the larger Sunrise Beach (Haad Rin Nok) to the north. The famous Full Moon Party takes place on Sunrise Beach each month.

The town and beach first became popular with backpackers escaping the tourist influx to Koh Samui in the 1980s. As the popularity of the beach and Full Moon Party have increased, the town has grown to accommodate the new visitors. The town is centred around Chicken Corner, a crossroads and popular meeting spot.

Haad Rin is the most popular spot on Ko Pha Ngan, largely for its thriving nightlife, with a long strip of clubs along Sunrise Beach that pump out the techno jams for drunken tourists to dance until dawn every night. This is also the home of the infamous Full Moon Party held once a month on or around the full moon. Tranquillity-seekers are advised to stay in town or on Sunset Beach, or better still, on a different beach altogether.

Haad Rin remains one of the best-known beaches in Thailand — with a long, wide swath of squeaky white sand and sea deep enough for good swimming even during lower tides, there's many reasons to come here apart from the party.

Had Rin is actually comprised of two popular beaches, Rin Nai beach on the west side of the peninsula and Rin Nok on the east side. From Rin Nai beach you can see Koh Samui very clearly. This is also a great place to catch the sunset. On the beach of Rin Nok is Bang Rak pier where the ferryboats from south Samui arrive and leave daily. Rin Nok beach is well known among Thai as well as the foreigner tourist for its “Full Moon Party”. This spot is ranked as the third most beautiful spot in the world to view the full moon.

In season, Haad Rin Nok (Sunrise Beach) is packed much of time by jet skis and hundreds of sunbathers, volleyballers and various other fun-seekers and sun-worshippers. Haad Rin Nai (Sunset Beach) is more peaceful and the resorts more reasonably priced, but the beach is not anywhere near as pretty. The much longer and narrower strip of sand is generally rougher, and the water is much shallower — really too shallow to swim in the lower tidal seasons (May to July).

Don't expect an authentic Thai experience here, but rather hordes of young western backpackers crowding the streets, watching movies and sitcoms in the restaurants by day and partying till they drop come the evening.

Travellers can find anything they might need in Haad Rin. ATMs and money exchange are plentiful, and every other shop is a travel agent or internet provider, or both. Most guesthouses and resorts here offer laundry service, and a plethora of mini marts, including 7-Elevens, pharmacies and nursing clinics are easy to find.

Most of the nightlife in the town is centred on beach-front spots. The original beach bars, Drop-In Bar and Cactus Bar attract the largest crowds, with nightly drinks promotions and fire shows. Here, popular chart tunes, R&B and club classics entertain the crowds. Other beach bars include Vinyl Club, Zoom (both playing psytrance, the original Full Moon Party style of music), Orchid (playing Drum and Bass and Jungle) and Boom Boom Bar (playing deeper house and trance music).

The Outback Bar is one of the drinking holes where many visiters' nights begin, situated further back from the beach in the centre of the town, where a large variety of European, American, Australian, and Thai food are served in a relaxed environment.

In recent years, the Floating Bar has been introduced, forming an alternative location for partiers to while away a few hours with freshly caught crab and oyster on the sundecks of the raft-based bar-restaurant before rejoining the beach via a traditional Thai long-tail boat. The Bar (thanks to its mobile nature) is located according to seasonal tides, alternating between Haad Rin Nok and Haad Rin Nai.

While there are a few massage parlours, this part of Thailand is largely devoid of the prostitution prevalent in other areas such as Phuket and Pattaya.

Apart from the music and bars on the beaches of Haad Rin, a famous feature of the Haad Rin are the spectacular nightly fire shows put on by individuals at the Cactus and Drop-In bars. Various firemasters specialise in the arts of Poi and Staff, performing mind-boggling and beautiful tricks to entertain the crowds. Many tourists are inspired by the shows and opt to take up daytime lessons [1] before joining the evening fire shows personally.

The Full Moon Party is an all-night beach party that takes place in Haad Rin on the island of Koh Phangan, Thailand on the night of every full moon.

The party was originally a small affair with a small number of backpacking travellers dancing through the night of the full moon, mainly to psychedelic trance music. The Full Moon Party gained fame quickly through word of mouth, and the event now draws a crowd in excess of 10,000 every full moon evening. The party carries on until the sun rises the next day. All the bars on the sunset beach of Haad Rin town stay open and play music such as drum and bass, house and reggae. The event has become a part of the itinerary of many travellers to Asia. Entry to the event is completely free. In recent years, local entrepreneurs have attempted to expand upon the event with spinoffs like the Half Moon Party and Black Moon Party.

Thai alcohol brands such as Sang Som rum, Mekong whiskey, and Singha beer are most popular among travellers. A signature of the Full moon party are the buckets - mixed drinks served in small plastic pails. A bottle of alcohol (usually Sang Som rum) is poured over ice and topped up with a can of Coke and a bottle of Red Bull syrup. Several straws are then thrown in. The price in 2006 for a bucket was around 200 baht

There have been a number of prosecutions recently over the sale of low grade 'moonshine' alcohol added to buckets. There have also been cases of buckets being laced Rohipnol.

In the past there has been some association with illegal drug use. Although the use, possession, and/or sale of drugs is illegal under Thai law, club drugs such as ecstasy, methamphetamine, Yaa Baa, marijuana, opium, mushrooms and even over the counter diet pills have been reported. As of 2002, the Thai government has pursued a stricter defense against illegal drugs at these events.

The standard 'fine' for possession is about 50,000 baht ($1200) and foreigners do go to jail for possession. Drug use at Full Moon Parties has lessened in recent years, in part due to greater fear of being caught but also because the parties now draw attendees from a wider range of backgrounds.