Traces of a Khmer road were clearly identified through examination of a series of aerial photographs covering the area from Wat Phu to Angkor. Some extensive sections of the road are still clearly visible at ground level. The road was built after the Khmer Empire was unified, when travelling through provinces was no longer too dangerous. The connection from the Wat Phu temple complex to Angkor again points to the enduring sacred significance of the temple and the Lingaparvata or Linga Mountain. The road was built of compacted earth and looks like a causeway. It can be easily recognised in some sections, but others are in poorer condition. Chapels or resting-places were built at regular distances along the road; an inscription at Preah Khan (a 12th century temple at Angkor) mentions 121 rest houses (dharmasala) along the route, and ruins of several of them have been found. Today there are a number of villages as well as other ancient monuments along the road, and bushes and trees have grown on it. It is often possible to make out its base, but the track is not always easy to follow without the assistance of an archaeologist. The road starts from the Nandin Hall at Wat Phu Champassak, leading some scholars to suggest that this building was originally a sacred chapel or resting house where pilgrims arriving via the road would stay for their first devotions. A walk of one hour south along the road through open country and woodland leads first to Nang Sida and further to Ban That (18 kilometres from Wat Phu).