Aerial photography has helped shed new light on the capital of Kublai Khan's empire, also known as Xanadu in Marco Polo's Travel Notes.

The description of the metropolis Shangdu (Xanadu) by Marco Polo some 700 years ago has somewhat been confirmed by aerial photography, Yang Lin, director of the center of remote sensing and aerial photography of China's National Museum, said on Saturday.

"We can see the spectacular city with its scale and the density of buildings," Yang said.

The ruins have been overgrown with grass for more than 600 years. Archaeologists have taken a large number of photos of the site in Zhenglan Banner in north China's Inner Mongolia Autonomous Region from planes flying at low altitudes in recent years.

By examining photos, archaeologists can tell the shape of the ancient site and where the relics are located at the site, according to Yang.

The capital Shangdu was built in 1256 under the command of Kublai Khan who was enthroned there four years later. It became a summer resort after the Yuan Dynasty (1271-1368) moved its capital to present-day Beijing and was destroyed during a peasant war at the end of the dynasty.

According to Marco Polo's Travel Notes, there were palaces made of marble in the city, with the rooms gilded and painted, and the palaces were so exquisite that people derived both visual and mental satisfaction.

"Since the capital has been dilapidated for many years, we were not clear about its layout. And because it is located in vast grassland, the inconvenient traffic condition makes it difficult to conduct archaeological research in traditional ways," said Yang.

"Through aerial photography, we can observe the remains which are difficult to be identified from ground," Yang said.

The photos show that the city is square with three concentric city walls. The outer wall was surrounded by a moat of 20 meters wide.

Inside the city, archaeologists said that they can tell remains of barns, barracks and horse stables. And relics of a dam for flood prevention have also been discovered at about two kilometers north and west of the city.

According to Marco Polo's Travel Notes, a wide road connects Shangdu and Dadu (today's Beijing) at that time, and along the road shops and merchants could be found everywhere.

This description has been proven to be true when aerial photos show remains of a wide road running from west to east at south of the city and leading to the depths of the grassland, said Yang.

"Aerial photography enables us to get new understanding of Shangdu. Combining the architecture of nomads and imperial buildings of the Han nationality, Shangdu occupies a significant status in China's history of capital construction," Yang added.

(Xinhua News Agency October 9, 2005)