LANZHOU, Aug. 31 (Xinhua) -- Restoration of the feet of a stone Buddha dating back 1,600 years in Tianti Mountain Grottoes, some of China's oldest, has been completed.

The Buddha statue in northwest China's Gansu Province was built on fragile red sandstone beside a reservoir. Water seepage and weathering damaged parts of the statue including the feet.

The restoration project was launched in May 2020.

The most difficult part was the repair work on the feet, which had suffered severe water seepage, according to Qiao Hai of the Dunhuang Academy, which carried out the restoration.

Workers drained water from the floor and rocks surrounding the stone Buddha, removed loose rock chunks, figured out the original size and features of the badly damaged feet, and brought it to its past glory, Qiao said.

The project can help protect the foundation of the historic statue and restore its overall integrity, Qiao added.

The Tianti Mountain Grottoes, among the prototypes of Yungang Grottoes and Longmen Grottoes, are called the "ancestor of grottoes" in the Chinese academic world. The grottoes were first built in the Eastern Jin Dynasty (317-420) and are under state-level protection.