limestone caves

Dehydrated, people living in Williamson County, Austin, Texas, USA called a mechanic to suddenly find out

Two almond-shaped holes on the ceiling of this limestone cave give visitors a feeling of being faced with God's eyes.

At first glance it seems that this boat has been blown into space and its crew is floating among the stars.

The fireflies on the 30 million-year-old limestone cave in New Zealand sparkle with light, making observers feel like standing under the starry sky.