Most pet cats will become timid or defensive when outdoors, but not Millie – after being adopted by her mountain-climbing owner Craig Armstrong, Millie has become a feline hiking and mountain-climbing legend.

Crampus from Netherworld Haunted House with Amber Thompson, spa staff, at Bliss Spa at W Atlanta Downtown hotel on Thursday, October 7, 2014. A self-guided, dark attraction known for its over-the-top special effects, intense make-up, costuming and stunt actors as well as unique monsters, unusual themes and chilling detail, Netherworld Haunted House in Atlanta is taking over the Halloween holiday this season for its 18th season. (Photo by Hyosub Shin/AJC)

A man lies on the floor during a ritual at the Sorte Mountain on the outskirts of Chivacoa, in the state of Yaracuy, Venezuela October 10, 2015. One long night every year in a mountainous rainforest in Venezuela, hundreds gather to dance on red-hot embers, enter trance-like states, and worship an ancient goddess known as Maria Lionza. Those who travel to the mountain known as Sorte in central Venezuela are practitioners of a cult that is built on local indigenous traditions. (Photo by Marco Bello/Reuters)

The sun rises between Sgurr nan Gillean and Knight’s Peak, Black Cuillin, Isle of Skye. (Photo by Adrian Trendall/Mountain Photo of the Year)

In this May 24, 2016 photo, a young boy descends the Qullqip'unqu mountain looking out at the tens of thousands of pilgrims gathered to celebrate the three-day festival Qoyllur Rit’i, translated from the Quechua language as Snow Star, in the Andean Sinakara Valley, in Peru's Cusco region. The celebration that mixes Catholic and indigenous beliefs honors Jesus as well as the area’s glacier, which is considered sacred among some indigenous people. While the native celebration is far older, the Christian part of the ritual stretches back to the 1700s, when Jesus is said to have appeared to a young shepherd in the form of another boy. (Photo by Rodrigo Abd/AP Photo)

“Award-winning photographer Camille Seaman, best known for her earlier work depicting massive polar icebergs, recently turned her lens on another incredible natural phenomenon - storm clouds above the American Midwest. She partnered with experienced storm chasers and began to stalk a particular type of storm cloud – the supercell. On June 22, 2012, in western Nebraska, she encountered an enormous supercell and captured its many faces”. (Photo by Camille Seaman via TheAtlantic)