“The Atlas moth (Attacus atlas) is a large saturniid moth found in the tropical and subtropical forests of Southeast Asia, and common across the Malay archipelago. Atlas moths are considered the largest moths in the world in terms of total wing surface area [upwards of c. 400 cm2 (62 sq in)]. Their wingspans are also amongst the largest, reaching over 25 cm (10 in). Females are appreciably larger and heavier”. – Wikipedia. Photo: Atlas Moth. (Photo by Terri Oda)

“Miniatur Wunderland is a model railway attraction in Hamburg, Germany and the largest of its kind in the world. As of January 2011, the railway consists of 12,000 metres (39,370 ft) of track in HO scale, divided into seven sections: Harz, the fictitious city of Knuffingen, the Alps and Austria, Hamburg, America, Scandinavia, and Switzerland. Of the 6,400 square metres (68,889 sq ft) of floorspace, the model takes 1,150 m2 (12,378 sq ft)”. – Wikipedia

Photo: Details of the “Miniatur Wunderland” are pictured on April 2, 2009 in Hamburg, Germany. The world's largest model railway and one of the most popular tourist attractions in Germany is located next to the Elbe in Hamburg's Speicherstadt. (Photo by Joern Pollex/Getty Images)

Ngorongoro Crater (Tanzania). At 610m deep and 260 sq km, this is the largest unflooded caldera in the world. A blue-green vision from above it's a haven for engangered wildlife and Maasai livestock. The crater was formed three million years ago when a giant volcano, which could have been as high as Kilimanjaro, exploded and collapsed. The caldera formed the concentric fractures in the crust cracked down to a magma reservoir deep underground. (Photo by John Bryant/Getty Images)

Unforgiving temperatures of up to 60℃ (140℉) beat down on these saltminers on a daily basis. The mines, situated in the Afar Triangle in Ethiopia, stretch across 38,000 sq miles and at their lowest point are more than 300ft below sea level. Joel Santos travelled to capture the area’s dry, brutal beauty. Here: Dromedaries and donkeys are used to transport the salt. (Photo by Joel Santos/Barcroft Images)

Moraine Lake is a glacially-fed lake in Banff National Park, 14 kilometres (8.7 mi) outside the Village of Lake Louise, Alberta, Canada. It is situated in the Valley of the Ten Peaks, at an elevation of approximately 6,183 feet (1,885 m). The lake has a surface area of .5 square kilometres (0.19 sq mi). The lake, being glacially fed, does not reach its crest until mid to late June. When it is full, it reflects a distinct shade of blue. The colour is due to the refraction of light off the rock flour deposited in the lake on a continual basis.

The Greenland ice sheet is a vast body of ice covering 660,235 sq miles, roughly 80% of the surface of Greenland. It is the second largest ice body in the world, after the Antarctic Ice Sheet. Some scientists predict that climate change may be near a "tipping point" where the entire ice sheet will melt in about 2000 years. If the entire 2,850,000 cubic kilometres (683,751 cu mi) of ice were to melt, it would lead to a global sea level rise of 7.2 m (23.6 ft).