Prang Khack is located between Phra Narai Rachanivej and the official, residence of ambassadors. It is not far from Phra Prang Sam Yod. In the former time, it functioned as a sacred place of the Brahmanism. It consists of three brick Prangs locating in a row arrangement, north-south. The one in the middle is the biggest that is in between the two prangs in smaller size.
All three Prangs have only one entrance in the east while the other three entrances are fake.
This ancient site is aged around the 10th century. This is determined by the architectural style of the Prang that is similar to Pha-Kho type of Khmer art (during 882-893). The similarity is the-way the two Prangs were built of brick.
The difference is that it was not coaled with plaster but connected with gum (sticky substance obtained from stems of trees). The door was built of stone but the way it was framed imitates the wooden door frame.