From Wikipedia

The Lost City
of Angkor Wat

Angkor Wat lies 5.5 km north of the modern town of Siem Reap, and a short distance south and slightly east of the previous capital, which was centred on the Baphuon. It is in an area of Cambodia where there is an important group of ancient structures. It is the southernmost of Angkor's main sites.

The initial design and construction of the temple took place in the first half of the 12th century, during the reign of Suryavarman II (ruled 1113 – c. 1150), Dedicated to Vishnu, it was built as the king's state temple and capital city. As neither the foundation stela nor any contemporary inscriptions referring to the temple have been found, its original name is unknown, but it may have been known as Vrah Vishnulok after the presiding deity. Work seems to have ended shortly after the king's death, leaving some of the bas-relief decoration unfinished. In 1177, approximately 27 years after the death of Sulyavarman II, Angkor was sacked by the Chams, the traditional enemies of the Khmer. Thereafter the empire was restored by a new king, Jayavarman VII, who established a new capital and state temple (Angkor Thom and the Bayon respectively) a few kilometres to the north.

In the late 13th century, King Jayavarman VIII, who was Hindu, was deposed by his son in law, Srindravarman. Srindravarman had spent the previous 10 years in Sri Lanka becoming ordained as a Buddhist monk. Hence, the new King decided to convert the official religion of the empire from Hindu to Buddhist. Given the constant political corruption of the time, citizens were quick to follow a faith founded on tranquility without a need for material gain and power. This made the conversion relatively easy.  Hence, Angkor Wat was converted from Hindu to Theravada Buddhist use, which continues to the present day. Angkor Wat is unusual among the Angkor temples in that although it was somewhat neglected after the 16th century it was never completely abandoned, its preservation being due in part to the fact that its moat also provided some protection from encroachment by the jungle.

One of the first Western visitors to the temple was Antonio da Magdalena, a Portuguese monk who visited in 1586 and said that it "is of such extraordinary construction that it is not possible to describe it with a pen, particularly since it is like no other building in the world. It has towers and decoration and all the refinements which the human genius can conceive of". However, the temple was popularised in the West only in the mid-19th century on the publication of Henri Mouhot's travel notes. The French explorer wrote of it:

"One of these temples—a rival to that of Solomon, and erected by some ancient Michelangelo—might take an honourable place beside our most beautiful buildings. It is grander than anything left to us by Greece or Rome, and presents a sad contrast to the state of barbarism in which the nation is now plunged."

Mouhot, like other early Western visitors, was unable to believe that the Khmers could have built the temple, and mistakenly dated it to around the same era as Rome. The true history of Angkor Wat was pieced together only from stylistic and epigraphic evidence accumulated during the subsequent clearing and restoration work carried out across the whole Angkor site.

There were no ordinary dwellings or houses or other signs of settlement including cooking utensils weapons or items of clothing usually found at ancient sites. Instead there is the evidence of the monuments themselves. 

Angkor Wat required considerable restoration in the 20th century, mainly the removal of accumulated earth and vegetation. Work was interrupted by the civil war and Khmer Rouge control of the country during the 1970s and 1980s, but relatively little damage was done during this period other than the theft and destruction of mostly post-Angkorian statues.