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.

Alain Robert, known as the French “Spiderman” climbs the “First” tower, the highest building in France on May 10, 2012 in Paris La Defense, Hauts de Seine, France. (Foto by DPA/AP Photo/Michel Euler)

Unloading a Cartopper from a UPRR work train at Port Barre Louisiana. Kinda scary to watch, but it worked like a charm.

Climbers ascend the walls of the Westway Climbing Centre on June 15, 2011 in London, England. The Westway indoor climbing centre is located under the A40 flyover in Shepherd's Bush has over 350 climbing routes, some of which rise to over 14 meters. (Photo by Oli Scarff/Getty Images)

Participants struggle to reach the prizes during a greased-pole climbing competition held as a part of the independence day celebrations in Jakarta, Indonesia, Sunday, August 17, 2014. Indonesia is celebrating its 69th independence from the Dutch colonial rule. (Photo by Dita Alangkara/AP Photo)

A Russian daredevil has captured a vertigo-inducing selfie – while standing on top of a Dubai skyscraper. Nineteen-year-old Alexander Remnev scaled the Princess Tower – the worlds tallest residential building at 1,350ft – before getting his camera out to take these stomach-churning pictures. Photo: He leans on the very top of the tower as he takes this vertigo-inducing picture. (Photo by Alexander Remnev/Caters News)

This is a story about how get to the top of the crane that mounted on the roof of the tallest building in Europe. So... its illegal and unsafe =)

Alain Robert of France, who is known as "Spiderman", climbs the Habana Libre hotel in Havana February 4, 2013. Robert, who scales buildings all over the world without safety equipment, successfully climbed the hotel which is 126 metres (413 feet) high. (Photo by Stringer/Reuters)