Koh Phangan is located in Jangwat (province) Suratthani in the Southern Gulf of Thailand and is part of the group of islands that make up the Samui Archipelago; a group of over 40 islands fashioned in granite from age old igneous formations.
The provincial capital is also called Suratthani and acts as the main overland transport hub for the islands. Koh Phangan is 70kms from the mainland and approximately 12kms away from Koh Samui which acts as the main air link to Koh Phangan.
Koh Phangan is most easily accessd via Koh Samui Airport though it is slightly cheaper to fly to the regional transport hub of Suratthani. From Koh Samui a fast boat takes only 25 minutes whereas the journey from the mainland takes around eight times longer. If you come overland, the overnight train is the best option with a frist class sleeper carriage ideal for families.
Buses are the most economic choice with a trip from Bangkok costing only about 650 Baht, all the way to Koh Phangan. Ferry services are more or less hourly throughout the day from Koh Samui and every couple of hours from the mainland; several boats also go regularly from Koh Tao.