John Gourley leans out of the cab of Goliath, one of Europe's largest cranes on September 20, 2011 in Rosyth, Scotland. The crane will begin the assembly of the Queen Elizabeth Class aircraft carriers later this week, when it lifts the first section of the two deck high 8,000 tonne centre block, which includes a section of the flight deck. The lift will mark the start of the Rosyth shipyards assembly of the first of two 65,000 tonne vessels the largest warships ever built for the Royal Navy. (Photo by Jeff J Mitchell/Getty Images)

Full-time feline photographer Andrew Marttila from Washington, D.C., captured blissful expressions of various cats on catnip, which he used to compile a book, “Cats on Catnip”. The photographer dedicated his time to capturing the euphoric expressions of kitties high on catnip – and the results are absolutely hilarious. (Photo by Andrew Marttila/Caters News Agency)

Malian workers haul out a boat they use to carry sand collected from the river bed during a routine maintenance on October 7, 2018, in the port of Bamako. Increasing construction in the Malian capital has boosted the demand for bricks made out of high-quality Niger River sand. (Photo by Michele Cattani/AFP Photo)

A model in Mongolia costumes prepares backstage in Xiangshawan Desert, also called Sounding Sand Desert on July 18, 2013 in Ordos of Inner Mongolia Autonomous Region, China. Xiangshawan is China's famous tourist resort in the desert. It is located along the middle section of Kubuqi Desert on the south tip of Dalate League under Ordos City. Sliding down from the 110-metre-high, 45-degree sand hill, running a course of 200 metres, the sands produce the sound of automobile engines, a natural phenomenon that nobody can explain. (Photo by Feng Li)

A couple passes the sculpture “Transformer” by Chinese artist Bi Heng during snowfall in Kassel, central Germany, Tuesday March 12, 2013. Frankfurt airport closed, a quarter of flights out of Paris were canceled, Belgium suffered record traffic jams and high-speed trains were stuck in stations – all because of a sudden dump of oddly late snowfall on Western Europe. Less prepared for the kind of heavy snow that regularly hits northern and eastern neighbors, France, Britain and Belgium struggled Tuesday to keep moving amid the frosty, blustery conditions. (Photo by Uwe Zucchi/AP Photo/Dpa)

The main church in the town of San Damian Texoloc, Mexico stands in front of the Popocatepetl volcano as is spews ash and vapor early Tuesday, July 9, 2013. Last Saturday, Mexico's National Center for Disaster Prevention raised the volcano alert from Stage 2 Yellow to Stage 3 Yellow, the final step before a Red alert, when possible evacuations could be ordered after the Popocatepetl volcano spit out a cloud of ash and vapor 2 miles (3 kilometers) high over several days of eruptions. (Photo by J. Guadalupe Perez/AP Photo)

Roof-topping enthusiast Daniel Lau takes a selfie with high-rise buildings down below as he stands on the top of a skyscraper in Hong Kong, China on August 15, 2017. A craze that began in Russia has now taken hold in Hong Kong, one of the world's most vertical cities. Mr Lau said he had been inspired by Russian climbers and that he was unafraid of the vertiginous heights he scales. (Photo by ImagineChina/Rex Features/Shutterstock)

The giant metal structure sits 330ft above the ground on the roof of a 22 storey office block in Dutch capital Amsterdam on September 6, 2016. Tourists sit in a playground-style chair as they propel themselves them over the edge of the building with only thin-air between them and the ground below. Engineers spent several years designing and building the breathtaking swing. By being fixed to the top of a building it reaches new heights – dwarfing other swings around Europe but trailing behind the 1,150ft high mechanical rides at the Stratosphere Hotel in Las Vegas, Nevada. (Photo by Huub Zeeman/SWNS.com)