More than 50 well-preserved volcano craters have been found near Qiongshan city in northern Hainan, China's southernmost island province.
A group of Chinese geologists who have just made an inspection trip to the area heralded the large number of craters, with intact lava tunnels, as a modern geological museum of volcanoes.
Historical records say that some 70 million years ago, northern Hainan had more than 30 volcanic eruptions, which produced the craters. Some of the bigger ones have now been opened to tourists, according to local sources.
The sources added that provincial government departments have also been preparing the site for inclusion on a list of geological relics enjoying state protection.