Khao Nam Khang National Park covers about 214 square kilometers across Na Thawi and Sadao districts in Songkhla Province, located along the Sankalakhiri mountain range which forms a natural border between Thailand and Malaysia. The area features complex mountainous terrain covered by dense tropical rainforest and montane forest, creating a highly intact ecosystem that serves as an important watershed for several river basins and remains ecologically connected to large forest areas in Malaysia. This connectivity supports rich biodiversity, including tropical plants, large hardwood trees, ferns, and wild orchids, as well as rare wildlife such as the Malayan tapir, the Black panther, and the Hornbill, all of which reflect the ecological richness of southern Thailand’s rainforest.

Historically, the area holds great significance as it once served as a major stronghold of the Malayan Communist Party during regional political conflicts in Southeast Asia between approximately 1967 and 1989. During this period, the famous “Khao Nam Khang Tunnel” was constructed as an extensive underground network carved manually into clay soil. The tunnel system stretches over 1 kilometer, consists of 3 interconnected levels, and includes up to 16 entrances and exits. It was designed as a fully functional underground settlement containing command rooms, meeting halls, a medical room, a radio communication center, and living quarters, demonstrating highly organized strategic planning and human adaptation to remote forest conditions.

In addition to its historical importance, the park also has a distinctive microclimate, particularly at Khao Nam Khang Peak, which rises about 648 meters above sea level. This area is known for having persistent dew on leaves and grass throughout the day, even under sunlight, due to high humidity, cooler temperatures compared to lowlands, and continuous airflow within the montane forest. These conditions create a unique microclimate that differs significantly from surrounding areas.

The park also features several natural attractions such as Ton Lat Waterfall and Ton Dad Fah Waterfall, both located in lush forest environments that are ideal for relaxation and nature study. Hiking trails throughout the park allow visitors to experience the forest’s biodiversity up close. Overall, Khao Nam Khang National Park represents a rare combination of political history, ecological richness, and adventure tourism, making it suitable for travelers seeking deep learning experiences alongside exploration of nature.

• By car: From Songkhla city, take Highway 407, continue onto Highway 408 (Songkhla–Na Thawi), then turn into Highway 4113 (Na Thawi–Ban Prakop) and follow the signs to the park.

• Wear non-slip shoes, as tunnel floors and waterfall trails can be wet and slippery.

• The tunnel has stairs and narrow passages; elderly visitors should be especially careful.

• Bring a flashlight or use a mobile phone for lighting in some darker sections.

• Best visiting period: December to May, when rainfall is low and trails are easier to walk.