Namtok Sam Lan National Park originally called “Khao Sam Lan National Park”, covers 4 districts: Mueang, Kaeng Khoi, Nong Khae and Wihan Daeng, and occupies an area of approximately 44 square kilometres or 27,856 rai. It was declared a national park on 2 June, 1981. October to January, which is during winter, is the best time to visit.
 The park comprises many tiny and large mountains with a plain in the valley. The highest summit is Khao Khrok with a height of 329 metres. It is the highest sightseeing spot where the panoramic view surrounding the centre of Saraburi and nearby districts can be clearly witnessed. During World War II, the Japanese soldiers used this spot to watch the movements of their opponents through binoculars. The condition of this area is still naturally abundant. Many wild animals can be witnessed such as pheasants, red jungle fowls, barking deer, monkeys, wild boars, and various kinds of birds such as the Asian fairy-bluebirds, the white-crested laughing thrushs, the lineated barbets, the green-billed malkoha, as well as, many types of butterflies. 

There are many waterfalls inside the national park such as “Namtok Sam Lan”. It features 3 levels of rock terraces similar to a staircase, and this is the origin of the waterfall’s name. It is 300 metres from the office of the National Park. There is also “Namtok Pho Hin Dat", approximately 300 metres from the park office. It is a single-levelled waterfall, suitable for swimming. In the area of the waterfall is a wide rock terrace with a gigantic Pho or Bodhi tree, extending its branches outward. Moreover, there is “Namtok Ton Rak Sai”, which is 400 metres from the park office and originates from the same stream as Namtok Pho Hin Dat. It is a single levelled waterfall. Its lively stream flows from the 7-metre high stone cliff to the basin below. Around the basin are many big and small rocks which can be used as the place for admiring the waterfall. There is a trail, connecting these waterfalls together, which takes approximately 2-3 hours to get back to the starting point without having to return the same way. The waterfall is most beautiful during the end of July until the beginning of October. Other interesting attractions are as follows:
 
Khao Ruak Reservoir is a small reservoir with a carrying capacity of 50,000 cubic metres. It is located between Khao Ruak and Khao Daeng and was constructed in 1980 with a sightseeing spot and venue for recreational activities such as kayaking, cycling a punting boat, swimming, etc.
 
Phra Phutthachai Tunnel is 12 kilometres from the park office. It is a one-way train tunnel which is 7 metres wide, 7 metres high and 1,197 metres long. It was constructed in 1994 and is the longest train tunnel in Thailand built by Thai people. It is at Khao Chong Ling on the border between Tambon Charoen Tham , Amphoe Wihan Daeng and Tambon Nong Pla Lai, Amphoe Mueang, Saraburi.
 
World War II Memorial of the Japanese Army (Khao Daeng) is 2 kilometres from the park office. It is a historical attraction. During World War II, the Japanese soldiers occupied the area of Khao Daeng as a military base and prison for captives. There remain traces of holes caused by the bombs left behind by the Japanese soldiers.  The constructions made by the Japanese soldiers are the commanding tunnel, trenches along the valley, the commanding room, a treasure room, and the bunker lines.

Ancient Chedi on Top of Khao Radar is assumed to have been constructed during the Ayutthaya period but was struck by the thunderbolt. At present, there are some traces left. Another historical importance is that the Japanese soldiers once used this place as a cannon base. 

Besides, there are 3 natural study routes; namely, 1) Khao Daeng route, a distance of 1.6 kilometres, 2) Sam Lan – Ton Rak Sai route, a distance of 3.2 kilometres, and 3) Sam Lan – Sap Pla Kang route, a distance of 4.5 kilometres. For the 3rd route, tourists can stay overnight. Please inform the national park officer in advance.

The admission is 100 baht for adults and 50 baht for children.

Accommodation and Facilities:  The park has three guesthouses provided for tourists, costing 600-2,400 Baht, a camp for 60 people, costing 6,000 Baht/night, and a camping site for tourists bringing their own camping gear. Besides, there are punting boats and canoes for rent. For more information, please contact the park office at Tel. 0 3622 5171-2 or at the National Park, Wildlife and Plant Conservation Department, Bang Khen, Bangkok, at Tel. 0 2562 0760, or at www.dnp.go.th.

To get there: The park is located on the Bangkok - Saraburi Road, on Highway No. 1, Phahonyothin Road, approximately 16 kilometres south of Saraburi. Departing from Bangkok, turn right to make a U-turn before reaching Km. 102 to Highway No. 3042 and 3046, respectively to the asphalt road for 8 kilometres.