The park is home to the world's smallest mammal, the Kitti's hog-nosed bat, which weighs only about two grams.
Sai Yok Yai Waterfall flows directly into the Khwae Noi River, a unique feature among Thai waterfalls.
King Rama V visited the Sai Yok Yai Waterfall in 1877, 1888, and 1891, documenting the location in his royal journals.
The area was part of the strategic route for the infamous Death Railway built by prisoners of war during World War II.
The park's limestone caves, such as Tham Lawa, feature extensive stalactite and stalagmite formations.
The park protects a significant portion of the Tenasserim Hills, which act as a natural border between Thailand and Myanmar.
Sai Yok National Park is centered around the Khwae Noi River in Kanchanaburi Province, Thailand. The park is renowned for the Sai Yok Yai Waterfall, which flows directly into the river. Visitors frequently stay in stationary raft houses moored along the riverbanks. The area contains significant limestone cave systems, most notably Tham Lawa and Tham Daowadueng. Historically, the park served as a campsite for Japanese soldiers during the construction of the Death Railway in World War II. The terrain consists of mountainous deciduous forest and karst topography. The park is home to the Kitti's hog-nosed bat, the world's smallest mammal, first discovered in the area in 1973. The river facilitates swimming and motorized boat excursions through the canyon-like landscape.
The wooden suspension bridge offering an elevated view of the Sai Yok Yai Waterfall.
Bring a waterproof bag for your belongings if you plan on renting a raft house.
Wear insect repellent with DEET to protect against mosquitoes found in the forest areas.
Carry a flashlight if you intend to explore the limestone caves independently.
Do not attempt to swim in the river near the waterfalls without a life jacket due to strong, unpredictable currents.
Dress modestly near park offices; avoid loud noise in cave systems to prevent disturbing local wildlife.
