Preah Nimith Waterfall or Khonfall located in Preah Vihearr province, on the Mekong River at the Cambodia-Lao border is a spectacular waterfall/cascade often referred to as Preah Nimith Waterfall or the Lbak Khoun waterfall. November to May is the prime time to visit for clear water with it being quite ‘muddy’ during the rainy season. You can get to the waterfall in about an hour from Steung Treng town. Some people also like to visit Preah Romkel and take a boat to see the Irrawaddy dolphin.

Preah Vihearr Temple is an ancient Khmer temple built during the period of the Khmer Empire, that is situated atop a 525-metre (1,722 ft) cliff in the Dângrêk Mountains, in the Preah Vihearr province, Cambodia. In 1962, following a lengthy dispute between Cambodia and Thailand over ownership, the International Court of Justice (ICJ) in The Hague ruled that the temple is in Cambodia. Affording a view for many kilometers across a plain, Prasat Preah Vihearr has the most spectacular setting of all the temples built during the six-century-long Khmer Empire. As a key edifice of the empire's spiritual life, it was supported and modified by successive kings and so bears elements of several architectural styles. Preah Vihearr is unusual among Khmer temples in being constructed along a long north–south axis, rather than having the conventional rectangular plan with orientation toward the east. The temple gives its name to Cambodia's Preah Vihearr province, in which it is now located, as well as the Khao Phra Wihan National Park which borders it in Thailand's Sisaket province, though it is no longer accessible from Thailand. On 7 July, 2008, Preah Vihearr was listed as a UNESCO World Heritage Site.

Koh Ker is a remote archaeological site in northern Cambodia about 120 kilometres (75 mi) away from Siem Reap and the ancient site of Angkor. It is a jungle filled region that is sparsely populated. More than 180 sanctuaries were found in a protected area of 81 square kilometres (31 sq mi). Only about two dozen monuments can be visited by tourists because most of the sanctuaries are hidden in the forest and the whole area is not fully demined. Koh Ker is the modern name for an important city of the Khmer empire. In inscriptions the town is mentioned as Lingapura (city of lingams) or Chok Gargyar (translated as city of glance, or as iron tree forest). Under the reign of the kings Jayavarman IV and Harshavarman II Koh Ker was briefly the capital of the whole empire (928–944 AD). Jayavarman IV enforced an ambitious building program. An enormous water-tank and about forty temples were constructed under his rule. The most significant temple complex, a double sanctuary (Prasat Thom/Prang), follows a linear plan and not a concentric one like most of the temples of the Khmer kings. Unparalleled is the 36-metre (118 ft)-high seven tiered pyramid, which most probably served as state temple of Jayavarman IV. Really impressive too are the shrines with the two meter 6 ft 7 in high lingas.

The archeological complex of Preah Khan Kampong Svay or Prasat Bakan (according to local pronunciation) or Bakan Svay Rolay is located 100 km east of Angkor, in Preah Vihearr province, Cambodia. It stands as the largest single religious complex ever built during Angkorian Era, as its exterior enclosure is about 5 km square, even if the isolated location makes it one of less visited Angkorian sites. There are few historical data about Preah Khan Kompong Svay. French scholars argued it had been founded in the 11th century, probably by Suryavarman I. It was a royal residence during the kingdom of Suryavarman II and even Jayavarman VII lived here, before recapturing the capital city of Yasodharapura from invading Chams in 1181, and improved the complex.

The Kulen Promtep Wildlife Sanctuary (Daen Chomrok Satprey Kulen Promtep) is one of the largest protected areas in Cambodia and was set aside to protect the critically endangered, possibly extinct Kouprey. It was created by Royal Decree in 1993. The Kulen Promtep Wildlife Sanctuary is one of the last places on the planet where the giant ibis, a critically endangered species, can be found. It is also the national bird of Cambodia. The sanctuary is supported with the help of private donations as well as through an ethical eco-volunteer program.