Italian artist Guiliano Mauri is the father of this spectacular Cattedrale Vegetale (Tree Cathedral), a unique building created out of rows of real living trees. Located at the foot of Mount Arera on the outskirts of Bergamo in Northern Italy, the cathedral is an ever-changing building that will be fully formed over the course of decades – when the trees outgrow their supporting columns and become a piece of natural architecture.

Cave of the Crystals or Giant Crystal Cave is a cave connected to the Naica Mine 300 metres (980 ft) below the surface in Naica, Chihuahua, Mexico. The main chamber contains giant selenite crystals (gypsum, CaSO4·2 H2O), some of the largest natural crystals ever found. The cave's largest crystal found to date is 12 m (39 ft) in length, 4 m (13 ft) in diameter and 55 tons in weight. The cave is extremely hot with air temperatures reaching up to 58 °C (136 °F) with 90 to 99 percent humidity. The cave is relatively unexplored due to these factors. Without proper protection people can only endure approximately ten minutes of exposure at a time.