![This photo taken Feb. 2, 2014, shows the wonders of the Ice Caves of the Apostle Islands National Lakeshore in in northern Wisconsin.(Photo/IC)](http://www.ecns.cn/hd/2018/07/05/2ed3ca917eaf4384acfa4ee481091112.jpg)
This photo taken Feb. 2, 2014, shows the wonders of the Ice Caves of the Apostle Islands National Lakeshore in in northern Wisconsin.(Photo/IC)
![Photo taken by British photographer Tim Nevvel shows the ice cave near the Jokulsarlon Lagoon in Iceland.(Photo/IC)](http://www.ecns.cn/hd/2018/07/05/0b70303afa9947428566d3cc7184daca.jpg)
Photo taken by British photographer Tim Nevvel shows the ice cave near the Jokulsarlon Lagoon in Iceland.(Photo/IC)
![Tour guide Shayne McGuire has released stunning images from her expeditions, showing the inside of Alaska\'s melting Mendenhall Glacier glowing a beautiful blue.(Photo/IC)](http://www.ecns.cn/hd/2018/07/05/47b59af0167643d99ccf30910e4696f2.jpg)
Tour guide Shayne McGuire has released stunning images from her expeditions, showing the inside of Alaska's melting Mendenhall Glacier glowing a beautiful blue.(Photo/IC)
![Each year, near the spring and autumn equinoxes, morning sunlight passes through the arch of Japan\'s Kameiwa Cave to create the image of a shining heart.(Photo/IC)](http://www.ecns.cn/hd/2018/07/05/83736dcb47c24d01bbb37156603ab22d.jpg)
Each year, near the spring and autumn equinoxes, morning sunlight passes through the arch of Japan's Kameiwa Cave to create the image of a shining heart.(Photo/IC)
![Photographer Mathis Dumas captures Jeff Mercier climbing inside the glacier, in an ephemeral cave of the Mer de Glace in France.(Photo/IC)](http://www.ecns.cn/hd/2018/07/05/2513200dd92a44bf884190752028ca03.jpg)
Photographer Mathis Dumas captures Jeff Mercier climbing inside the glacier, in an ephemeral cave of the Mer de Glace in France.(Photo/IC)
![British adventure photographer Robbie Shone descended into the Gorner Glacier near Zermatt in Switzerland to capture spectacular pictures of ice caves.(Photo/IC)](http://www.ecns.cn/hd/2018/07/05/765e136815874341ad57f87d4abdee3c.jpg)
British adventure photographer Robbie Shone descended into the Gorner Glacier near Zermatt in Switzerland to capture spectacular pictures of ice caves.(Photo/IC)