This is an ice cave, known as "crystal Cave" on the frozen lagoon of the Svínafellsjökull glacier in Skaftafell, Iceland. This snow, which is up to 1000 years old has metamorphosed into highly pressurized glacier ice that contains almost no air bubbles.
Great wall of China. My eyes will never forget this site. As a child I thought it was the most wonderful place to sit and dream. China you will for ever have a place in my heart! for your travel bucket list