GUIYANG, Oct. 3 (Xinhua) -- An "egg-laying" cliff in southwest China has attracted a lot of interest online recently.

The cliff, located in Sandu County, Guizhou Province, has scores of egg-shaped rocks sitting on its edge. Most rocks are the size of a football, while smaller ones are still embedded inside the cliff, with only parts of them protruding out.

The amazing geological formation was recently reported online by China Daily.

According to the local government, the cliff is in a scenic area that has been open to public since 2010. It is about 100 meters long and five meters high. Local residents said that some "eggs" fall off the cliff every 30 years, "like a hen laying eggs."

At the bottom of the cliff lie many rocks that fell down in the past. Most of them are round or oval with a diameter of up to 50 centimeters. The green rocks are hard and have marks like the annual rings of tree trunks.

"In the past, people thought the rocks were auspicious and took them home," said resident Lu Renli. The largest rock collected weighs about 300 kg, with a diameter of 60 centimeters.

"It's called 'the king of eggs,'" Lu said.

Geologists have said that Guizhou was once a large ocean, and that the rock eggs could have been formed by a marine substance.