Underwater world

"Our water recycling system and deep-water lighting system have greatly improved the preservation of the relics," Huang said.

In the early days, the museum had to shut down periodically due to the deteriorating water quality in the container and a massive growth of algae on the rock. But now the water recycling system can balance the pressure in the container and purify the water.

Also, the system collects data about the river water level and flow speed in order to reduce the impact of the water pressure on the ridge.

"We inject 20 tons of purified water into the container every hour," says Huang. "It is a huge amount of work."

In addition, divers go into the container to clean the rock every month.

The container is equipped with a deep-water lighting system which improves the presentation of the inscriptions and reduces the power consumption.

"Most importantly, it reduces the light intensity and prevents the growth of algae on the rock," he adds.

Also, to offer visitors a clear view of the ridge, the museum recently changed the type of glass used in the windows, replacing them with materials developed for the aviation industry.