A substantial number of ancient Khmer monuments including temple, city, civil engineering structures and other features are preserved in Cambodia. Although vigorous research and conservation activities have progressed for more than one century, these efforts have been focused on the works in the ancient capital city, Angkor and its monuments, rather than the other regions of the past territory of the Khmer empire. The Sambor Prei Kuk monuments, which is also one of the remote sites from central area (Angkor) in the Angkorian period, conservation and research works was carried out by EFEO in the first half of the 20th century. However, it still requires advanced research and conservation works for identifying and maintaining its significant historical value. In particular, the severe concern for Sambor Prei Kuk is due to the fragile main structures of brick under a long deterioration process after the decline of Angkor empire. In addition, impacts during the Vietnamese war and civil conflicts in the past century also increased damage to their integrity.

All remnants of the ancient Khmer civilization provide significant evidence to understand the past history. However, the site of Sambor Prei Kuk is one of the most important historical sites with significant value for clarifying the early stage of ancient Khmer history. There are many temple structures preserved in the eastern area of the archaeological site. These concentrated architectural and sculptural works are exceptional in Southeast Asia during the late 6th early 7th century. These works show a sophisticated artistic sense and reached a high technical level, as well as a site identified as the authentic origin of the ancient Khmer arts. The western half of the archaeological site is occupied by the moated city area. This city might be identified as one of the oldest preplanned cities in Southeast Asia which was inspired by an Indianized urban concept.

Sambor Prei Kuk was generally identified to the Ishanapura which was the capital city of Pre-Angkorian period. However, some of the previous research found the evidence of activities in an earlier period than the 7th century. Additionally, some traces of renovation and additional structures were also confirmed to prove the continuous or intermittent use in the Angkorian period. Thus, this city, which is the capital city of the pre-Angkorian period, has been evaluated as the significant evidence of the national formative period of the ancient Khmer empire. In addition, this group of monuments is the significant evidence to understand the succession of Khmer history from the early stage of the pre-Angkorian period to the late Angkorian period.