The city of Lingapura, located just to the south of the Wat Phu Champassak Temple Complex, was built and occupied from the 9th through to the 13th century, around the time that the Khmer Empire was ruled from Angkor, in present day Cambodia. The name comes from linga (phallic symbol of Shiva) and pura (city) and refers to the close proximity of Lingaparvata or Linga Mountain, which continued to be sacred long after the power of Khmer empire had shifted to Angkor. The city was focused on the temple of Nang Sida. The remains of Lingapura are in the area known as Hong Nang Sida. Lingapura and its twin city of Setapura could be considered 'lost cities', because they were known only from inscriptions and literary evidence until recent archaeological survey work rediscovered them. Today, both cities are almost completely buried under rice fields and villages, except for the lumps in the plain which cover the remains of temples, ponds, barays or other brick structures. These sites are very significant because they represent some of the earliest known and studied urban sites in South East Asia.