Thung Salaeng Luang National Park: Protected Landscape and Geographic Context in Phitsanulok Province

Thung Salaeng Luang is best known for its exceptional savanna landscapes, which are relatively rare in Thailand. The park contains extensive meadows and grassland plains that create a distinctive visual character unlike the dense tropical forests found in most other Thai national parks. The park is also renowned for its impressive cave systems, particularly Tham Phra Wang Daeng, a 13-kilometer-long cave that hosts millions of bats. The multiple waterfalls, including Kaeng Sopha with its three tiers, and the Pong Sai salt licks in the northwest attract both researchers and visitors. The limestone hill formations, particularly around Khao Khae, provide dramatic scenery and harbor unique ecological communities.

Thung Salaeng Luang was first proposed for inclusion in Thailand's national parks system in 1959. The area was officially declared as the country's third national park in 1963, initially covering approximately 1,282 square kilometers. However, at the request of the Thai Army, approximately 20 square kilometers were withdrawn from the park's boundaries in the early years. This adjustment led to a formal 'reestablishment' of the park on May 27, 1975, with the current confirmed area of approximately 1,262 square kilometers or 789,000 rai. The park's establishment represented an early commitment by Thailand to protecting its natural heritage, following Kaeng Krachan and Khao Yai as the first two national parks. During the period from the late 1960s through the early 1980s, the park's forest areas served as operational territory for guerrillas of the Communist Party of Thailand. This historical period has left some environmental impacts on the park's ecosystems, though subsequent conservation efforts have worked to restore and protect the area. Today, the park is managed by the Department of National Parks, Wildlife and Plant Conservation.

The topography of Thung Salaeng Luang National Park is defined by a series of limestone hills and ridges rising dramatically from the surrounding terrain. The highest peak, Khao Khae, reaches 1,028 meters and offers panoramic views over the park's diverse landscapes. The elevation across the park ranges from 300 meters in the lower valleys to this highest point, creating significant variation in habitat conditions. The landscape is punctuated by numerous streams that originate within the park's boundaries, feeding into the Wang Thong River system. The park features extensive meadows, particularly in the southern sections, where savanna conditions support distinctive grassland ecosystems. Two notable salt licks exist within the park: Pong Sai in the northwest and Pong Thung Phaya in the southwest, areas that attract wildlife seeking essential minerals. The savanna areas, including Thung Nang Phaya at approximately 5 square kilometers and the larger Thung Salaeng Luang savanna at about 10 square kilometers, represent some of the most distinctive landscape features. Rock formations and cliff faces are scattered throughout, particularly around the limestone outcrops.

The ecological diversity of Thung Salaeng Luang is remarkable, with the park supporting no fewer than six distinct forest types within its boundaries. Hill evergreen forest dominates the higher elevations, often shrouded in mist and supporting moisture-loving plant communities. Conifer forests, particularly those dominated by Pinus latteri, occur in specific locations, while tropical evergreen forest occupies the more humid valley bottoms. Dry evergreen forest covers substantial areas, and mixed deciduous forest creates seasonal color changes as trees drop their leaves. At lower elevations, dry dipterocarp forest characterized by species of Shorea and Dipterocarpus creates another distinct ecological zone. The botanical inventory is extensive, with evergreen species including numerous oaks, magnolias, and conifers, while dipterocarps such as Shorea siamensis, Dipterocarpus alatus, and Hopea odorata dominate certain areas. The park also supports interesting flowering plants including orchids such as Gastrochilus bellinus and Spathoglottis pubescens, as well as carnivorous plants including several Drosera and Utricularia species.

Thung Salaeng Luang supports a diverse faunal community, with approximately 170 bird species recorded within the park. Of these, about 115 are passerine species from 37 families, including numerous babblers, warblers, and flycatchers. Non-passerine species number around 55 from 20 families, including the Indochinese roller, oriental pied-hornbill, and various raptors. Mammals recorded in the park include barking deer, golden jackal, and black giant squirrel, though larger species are less commonly observed. Reptile diversity includes the Asian water monitor, reticulated python, and the big-headed turtle, while amphibians such as the banded bullfrog and Hong Kong whipping frog inhabit wetland areas. The aquatic community includes species such as the Siamese mud carp, horseface loach, and the emerald green betta. Butterfly species include the banded marquis and common archduke. The salt licks at Pong Sai and Pong Thung Phaya provide important mineral sources for wildlife and create opportunities for observing animals, particularly in early morning and late afternoon.

As one of Thailand's earliest national parks, Thung Salaeng Luang represents an important conservation legacy and demonstrates the country's commitment to protecting natural ecosystems. The park's varied habitats, from savanna to cloud forest, protect ecological communities that would otherwise face significant pressure from agricultural expansion and development. The cave systems, particularly Tham Phra Wang Daeng, provide critical roosting habitat for millions of bats, supporting ecological functions including pollination and insect control across wider areas. The savanna habitats are themselves significant, as such ecosystems are limited in Thailand and face ongoing threats from fire and land conversion. The park also protects watersheds that feed the Wang Thong River system, providing hydrological benefits that extend beyond park boundaries. However, the park has faced challenges from historical human activity, including the period of communist insurgency and ongoing pressure from hill tribe communities and other intruders who have at times impacted flora and fauna. Management efforts continue to address these challenges while balancing access with protection.

Thung Salaeng Luang holds significance beyond its ecological value as one of Thailand's traditional protected areas. The park's name is believed to derive from the Salaeng tree, a species once common in the area, combined with 'Thung' meaning field or plain, reflecting both the landscape character and the presence of this particular tree species. The park occupies territory that has been inhabited by various communities over time, and the influence of hill tribes and other local populations has shaped both the landscape and the park's management history. The area's historical use by Communist insurgents during the political turmoil of the 1960s and 1970s represents a significant chapter in the region's story, though this period has passed. The caves, particularly those used for religious purposes such as Tham Phra Rod-Maree, reflect the spiritual relationship some local communities have had with the landscape. Today, the park represents a space where traditional land use practices and conservation priorities must be balanced.

Thung Salaeng Luang offers visitors multiple distinctive attractions that set it apart from other Thai national parks. The savanna landscapes, particularly the expansive Thung Salaeng Luang meadow covering about 10 square kilometers, create vistas reminiscent of African grasslands, a rare sight in Southeast Asia. Kaeng Sopha waterfall drops in three tiers along the Wang Thong River, offering scenic beauty and accessible viewpoints. Tham Phra Wang Daeng, stretching 13 kilometers in length, provides an extraordinary underground exploration opportunity and hosts impressive bat colonies that emerge at dusk. The network of other caves including Tham Duan, Tham Dao, and Tham Sai-Ngarm adds speleological interest. The park's position in the Phetchabun Mountain Range, which forms a natural boundary between Phitsanulok and Phetchabun Provinces, creates dramatic mountain backdrops. The Pong Sai salt lick areas provide wildlife viewing opportunities, particularly during quieter periods of the day.

The optimal time to visit Thung Salaeng Luang is during the cool dry season from November through February, when temperatures are most comfortable for outdoor activities and the landscape is at its greenest following the monsoon rains. Average temperatures hover around 25 degrees Celsius, though conditions can feel warmer during late spring and early summer when temperatures often reach 30 degrees. The period from November to February offers the most pleasant hiking conditions and clearer visibility for mountain views. The monsoon season from May through October brings higher rainfall, with the park receiving approximately 1,700 millimeters annually, which can limit some activities but also transforms the waterfalls and supports lush vegetation. Visitors should note that malaria has historically been present in the park area, so appropriate precautions and consultation with health professionals regarding prevention measures is advisable, particularly for extended stays or camping.