A Hypsiboas crepitans frog is pictured at a terrarium in Caracas November 30, 2015. Venezuelan frogs and toads are in critical danger due to climate change as rising temperatures complicate reproduction and spread a deadly fungus, say scientists, who liken the species to canaries in a coalmine warning of imminent danger. The survival of a group of nearly 20 frog and toad species, which top Venezuela's list of endangered species, may rest on a small group of academics in a Caracas laboratory attempting to recreate the amphibians' natural reproductive conditions. (Photo by Carlos Garcia Rawlins/Reuters)

Socialite Kathy Hilton attends the Prudential Financial Grand Prix Hamptons Classic Horse Show August 31, 2003 in Bridgehampton, New York.

A deer forages for food in the early morning sun as cooler temperatures bring on the autumn season at Dunham Massey on on October 11, 2010 in Lymm, England. Shortening daylight hours and cooler weather brings on the rutting season for Red and Fallow deer herds and Autumn foliage colours across Britain. (Photo by Christopher Furlong/Getty Images)

Dancers of the English National Ballet perform MacMillan's The Rite of Spring from Beyond Ballet Russes with costumes by Kinder Aggugini at the Coliseum on March 22, 2012 in London, England. (Photo by Ian Gavan/Getty Images)

Locals re-enact the 1573 medieval battle of “Seljacka Buna” in Donja Stubica February 7, 2015. (Photo by Antonio Bronic/Reuters)

The Grand Canyon Skywalk is a transparent horseshoe-shaped cantilever bridge and tourist attraction in Arizona near the Colorado River on the edge of a side canyon in the Grand Canyon West area of the main canyon. USGS topographic maps show the elevation at the Skywalk's location as 4,770 ft (1,450 m) and the elevation of the Colorado River in the base of the canyon as 1,160 ft (350 m), and they show that the height of the precisely vertical drop directly under the skywalk is between 500 ft (150 m) and 800 ft (240 m).

The three peaks of Lavaredo, or the “Tre Cime di Lavaredo” in Italian, are three distinctive battlement-like peaks, in the Sexten Dolomites of northeastern Italy. They are probably one of the best-known mountain groups in the Alps, and one of the most photographed in Italy. The three peaks are named, from east to west, "little peak" (Cima Piccola), "big peak" (Cima Grande) and "western peak" (Cima Ovest). The Cima Grande has an elevation of 2,999 metres (9,839 ft). It stands between the Cima Piccola, at 2,857 metres (9,373 ft), and the Cima Ovest, at 2,973 metres (9,754 ft).