In this Monday, January 18, 2016 photo, Iranian rock climber, Farnaz Esmaeilzadeh, scales a climbing gym in the city of Zanjan, some 330 kilometers (207 miles) west of the capital Tehran, Iran. Esmaeilzadeh, 27, who has been climbing since she was 13, has distinguished herself in international competitions despite the barriers she faces as a female athlete in conservative Iran. (Photo by Ebrahim Noroozi/AP Photo)

Participants compete in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. Thousands of athletes got covered in mud as they celebrated International Mud Day running a 13-kilometer obstacle course on a sunny Saturday with heatwave-like temperatures up to a 29 degrees Celcius (around 84 degrees Fahrenheit). (Photo by Juan Medina/Reuters)

The Angel Oak Tree is a Southern live oak located in Angel Oak Park on Johns Island near Charleston, South Carolina. The Angel Oak Tree is estimated to be at least 400 years old[citation needed]. It stands 66.5 ft (20 m) tall, measures 28 ft (8.5 m) in circumference, and produces shade that covers 17,200 square feet (1,600 m2). Its longest branch distance is 187 ft. in length. Angel Oak was the 210th tree to be registered with the Live Oak Society.

American free climber Dean Potter walks on a 41-meter-long and two-centimeter-wide slackline over Enshi Grand Canyon at an altitude of 1,800m on April 22, 2012 in Enshi, Hubei Province of China. Potter successfully finished the lone slackline walk in about three minutes without taking any protective measures. (Photo by ChinaFotoPress/ChinaFotoPress)

Dramatic photos show the measure of a man in contrast to the enormity of nature.
A series of photos from the Humboldt State University Library capture lumberjacks working among the redwoods in Humboldt County, California.
The photos are part of the Ericson Collection....

SEE ALSO: «Huge Plants» AND «Loggers»

Measuring just five feet at its widest point, the ultra-thin home was unveiled in the Polish capital of Warsaw on Sunday, October 21, 2012. Photo: The Keret House is squeezed into the space between two apartment buildings in Warsaw. There's a four-inch gap between the apartment buildings to either side. A perforated steel facade was used to allow in more light. (Photo by Andrea Meichsner/The New York Times)

People in boats approach “Die Badende” (“The Bather”), a giant sculpture showing a woman's head and knees as if she were resting in the Binnenalster lake on August 3, 2011 in Hamburg, Germany. The sculpture, which is made of styrofoam and steel and measures 4 meters high and 30 meters long, is a project by artist Oliver Voss and will be on display for the next ten days. (Photo by Sean Gallup/Getty Images)

The Seven Sisters is the 39th tallest waterfall in Norway. The waterfall consists of seven separate streams, and the tallest of the seven has a free fall that measures 250 metres (820 ft). The waterfall is located along the Geirangerfjorden in Stranda Municipality in Møre og Romsdal county, Norway. The waterfall is located just south of the historic Knivsflå farm, across the fjord from the old Skageflå farm. The falls are about 6.5 kilometres (4.0 mi) west of the village of Geiranger. It is part of the Geiranger World Heritage Site.