The name Siem Reap means the Siamese defeated, today’s Thailand, and refers to the victory of the Khmer Empire over the army of the Thai kingdom of Ayutthaya in the 17th Century. In 1907 Angkor, which had been under Thai control, was returned to Cambodia and the EFEO (École Française d'Extrême Orient) took responsibility for clearing and restoring the whole site. In the same year, the first tourists arrived in Angkor Wat - an unprecedented 200 of them in three months. Angkor had been 'rescued' from the jungle and was assuming its place in the modern world. Siem Reap today, being a popular tourist destination, has a large number of hotels and restaurants. Most smaller establishments are concentrated around the Old Market area, while more expensive hotels are located between Siem Reap-Angkor International Airport and the town along National Road 6. There are a variety of mid-range hotels and restaurants along Sivatha, and budget to mid-range hotels in the Phsar Leu area.
Is the largest temple in the world, with a volume of stone equaling that of the Cheops pyramid in Egypt. It is unlike all the other Khmer temples in that it faces west, and it is inspirit by 12th century Hinduism. Conceived by Suryavarman II, Angkor Wat took several decades to build. It is generally believe to have been a funeral temple for the king. Intricate bas relief surround Angkor Wat on four sides. Each tells a story. The most celebrated of these is the Churning of the Sea of Milk, which is located on the east wing. 
The ancient walled of Angkor Thom (Great City) contains the famous Bayon Temple with its more than 200 enormous, mysterious smiling faces. It also contains the 300 meter long Elephant Terrace with its large sculptured royal elephants and Garudas. Also within the walled area is the terrace of the Leper King. A sandstone replica of the Leper King is here.
Ta ProhmTa Prohm is the temple that has been left largely in its natural state since its discovery. Surrounded by jungle, its labyrinth stone hallways is overgrown with the roots and limbs of the massive Banyan trees which envelope the stone like tentacles. It was a place where Tomb Raider film made.
Banteay SreiBantey Srei is located about 32 km from Angkor and it is one of the oldest temples in the regions. This is the fable pink temple of the women, so called because it is made of pink sandstone and considered a tribute to the beauty of women. Its small size, delicate carvings and remarkable state of preservation make Bantey Srei one of everyone’s favorite temples.
Rolous Group
The three monument in the Rolous Group, located 12 km, southeast of Siem Reap, offer a look at the earliest definition of Khmer civilization. These temples, Bakong, Lolei and Prea Ko, were built in the 9th century under Indravarman I, Bakong is also the site of a modern Buddhist monastery.
Phnom Kulen
Dated in 9th century during reign of king Jasovarman II for Hinduism. Phnom Kulen is widely regarded as the birth place of the ancient Khmer Empire.
This site is regarded by the Khmers as one of the holiest sites because it is located at the origin of the Siem Reap river which was (and still is) the life giving source of the water that enable the widespread rice cultivation in the area of Angkor. As such it was the basis of the wealth of the civilization, which in its turn provided the resource of required tobuild the temples. At this site one can observe the beautiful rock carvings under the surface of the following water of Siem Reap river in the sitting of dense jungle.
Kbal Spean
Great Lake (Tonlé Sap Lake)
Cambodia’s Great Lake, in Khmer refers to Boeung Tonle Sap (Large Fresh Water River) but more commonly translated as GreatLake, is the most prominent feature on the map of Cambodia. Great Lake is a combined lake and river system of huge importance to Cambodia. It is the largest freshwater lake in South East Asia and is an ecological hotspot that was designated as a UNESCO biosphere in 1997. More than 100 varieties of waterbirds including several threatened and endangered species, over 200 species of fish, as well as crocodiles, turtles, macaques, otter and other wildlife inhabit the inundated mangrove forests. The Lake is also an important commercial resource, 
providing more than half of the fish consumed in Cambodia. In harmony with the specialized ecosystems, the human occupations at the edges of the lake is similarly distinctive - floating villages, towering stilted houses, huge fish traps, and an economy and way of life deeply intertwined with the lake, the fish, the wildlife and the cycles of rising and falling waters.
The lake sits only about 15 km south of Siem Reap town. If you take the ferry between Phnom Penh and Siem Reap you will cross the lake and dock at the village of Chong Khneas. There are several ways to see the culture and wildlife of the lake area depending on the amount of time you have and your interest.
Prek Toal Bird Sanctuary
The 'bird sanctuary' at the Prek Toal core area of the Tonle Sap Biosphere Reserve has been called "the single most important breeding ground in Southeast Asia for globally threatened large waterbirds." The Biosphere covers 31,282 hectares at the northwest tip of the Tonle Sap Lake and plays host to species including Greater and Lesser Adjuncts, Black-headed Ibis, Painted Stork, Milky Stork, Spot-billedPelican, Grey-Headed Fish Eagle and many more species. Of the three Biosphere core areas on the Tonle Sap Lake, Prek Toal is the most accessible from Siem Reap and the most popular with birdwatchers. The best time of year for viewing is the dry season when flocks of migratory birds congregate at Prek Toal. As the dry season progresses and the water recedes, the number of birds increases but the travel to some of the more important viewing areas becomes more difficult.
Kampong Phluk
Kampong Phluk is a cluster of three villages of stilted houses built within the floodplain of the Tonle Sap about 16 km southeast of Siem Reap. The villages are primarily Khmer and have about 3000 inhabitants between them. Flooded mangrove forest surrounds the area and is home to a variety of wildlife including crab-eating macaques. During the dry season when the lake is low, the buildings in the villages seem to soar atop their 6-meter stilts exposed by the lack of water. At this time of year many of the villagers move out onto the lake and build temporary stilted houses. In the wet season when water level rises again, the villagers move back to their permanent houses on the floodplain, the stilts now hidden under the water. Kampong Phluk's economy is, as one might expect, based in fishing, primary in shrimp harvesting. Kampong Phluk sees comparatively few foreign visitors and offers a close look at the submerged forest and lakeside village life as yet unperturbed by tourism. The area can be reached by boat from the Chong Khneas or by a combination of road and boat. By road/boat, take a car or moto to Roluos village just off Route #6 east of Siem Reap and the take a boat through the flooded forest the rest of the way to the village. During the dry season the road is clear and you can drive all of the way to the village.