Satun province

Perlis (Kedah Malay (Perlis dialect): Peghelih) is a state of Malaysia in the northwestern coast of Peninsular Malaysia. It is the smallest state in Malaysia by area and population. The state borders the Thai provinces of Satun and Songkhla to the north and the Malaysian state of Kedah to the south. Perlis is the only Malaysian state that is not divided into districts, due to its small size, but it is still divided into several communes. It was called Palit (Thai: ปะลิส) by the Siamese when it was under their influence. Perlis had a population of 227,025 as of the 2010 census.

Perlis experiences a tropical monsoon climate. Much of the state's highlands are part of the Nakawan Range, a subrange of the Tenasserim Hills system that spans through southern Myanmar, Southern Thailand and the Peninsular Malaysia, with Mount Perlis as the highest point at 733 m. The Nakawan also forms a natural frontier between Perlis and Thailand.

Songkhla (Thai: สงขลา, pronounced [sǒŋ.kʰlǎː], Malay: Singgora) is one of the southern provinces (changwat) of Thailand. Neighboring provinces are (from west clockwise) Satun, Phatthalung, Nakhon Si Thammarat, Pattani, and Yala. To the south it borders Kedah and Perlis of Malaysia.

In contrast to most other provinces, the capital Songkhla is not the largest city in the province. The much newer city of Hat Yai, with a population of 359,813, is considerably larger, with twice the population of Songkhla (163,072). This often leads to the misconception that Hat Yai is the provincial capital.

Trang (Thai: ตรัง, Thai pronunciation: [trāŋ]; Malay: Terang), also called Mueang Thap Thiang, is one of the southern provinces (changwat) of Thailand, on the west side of the Malay Peninsula facing the Strait of Malacca. Neighboring provinces are (from north clockwise) Krabi, Nakhon Si Thammarat, Phatthalung, and Satun.

Trang was formerly a port involved in foreign trade. It was the first place where rubber was planted in Thailand. Phraya Ratsadanupradit Mahison Phakdi brought rubber saplings from Malaya and planted them here in 1899, and rubber is now an important export of the country. The Trang River flows through the province from its origin in the Khao Luang mountain range, and the Palian River flows from the Banthat mountains. The province of Trang has an area of approximately 5,000 square km and 199 km of Strait of Malacca shoreline.

Phatthalung (Thai: พัทลุง, pronounced [pʰát̚.tʰā.lūŋ]) is one of the southern provinces (changwat) of Thailand. Neighboring provinces are (from north clockwise) Nakhon Si Thammarat, Songkhla, Satun, and Trang. Phatthalung is essentially a landlocked province, one of the only two in southern Thailand, the other being Yala.