Ranong is one of Thailand's southern provinces (changwat), on the west coast along the Andaman Sea. It has the fewest inhabitants of all Thai provinces (making it the least populous of all the Thai provinces). Provinces neighboring Ranong are (clockwise) Chumphon, Surat Thani, and Phang Nga. To the west, it borders Kawthaung, Tanintharyi, Myanmar.
Chumphon (Thai: ชุมพร, pronounced [t͡ɕʰūm.pʰɔ̄ːn]) is a southern province (changwat) of Thailand on the Gulf of Thailand. Neighbouring provinces are Prachuap Khiri Khan, Surat Thani, and Ranong. To the west it borders the Burmese province of Tanintharyi.
The Kra Isthmus (Thai: คอคอดกระ, pronounced [kʰɔ̄ː kʰɔ̂ːt kràʔ]; Malay: Segenting Kra), also called the Isthmus of Kra in Thailand, is the narrowest part of the Malay Peninsula. The western part of the isthmus belongs to Ranong province and the eastern part to Chumphon province, both in Southern Thailand. At its narrowest point, between the Thai cities of Kra Buri and Chumphon, the coastal distance between the Andaman Sea and the Gulf of Thailand is only 44 km (27 mi).
The Kra Isthmus marks the boundary between two sections of the mountain chain which runs from Tibet through the Malay peninsula. The southern part is the Phuket Range, which is a continuation of the Tenasserim Hills, extending further northwards for over 400 km (250 mi) beyond the Three Pagodas Pass.
Kra Buri (Thai: กระบุรี, pronounced [kràʔ bū.rīː]) is the northernmost district (amphoe) of Ranong province, southern Thailand.
Phang Nga (Thai: พังงา, pronounced [pʰāŋ.ŋāː]) is one of the southern provinces (Changwat) of Thailand, on the shore of the Andaman Sea to the west and Phang Nga Bay to the south. Neighbouring provinces, from north and moving clockwise, are Ranong, Surat Thani, and Krabi. Towards the south of Phang Nga is the Phuket province, connected by the Sarasin Bridge.