“Wells Cathedral is a Church of England cathedral in Wells, Somerset, England. Built between 1175 and 1490, Wells Cathedral has been described as “the most poetic of the English Cathedrals”. The Wells clock, an astronomical clock, is located in the north transept. The surviving mechanism, dated to between 1386 and 1392, was replaced in the 19th century, and was eventually moved to the Science Museum in London, where it continues to operate. It is the second-oldest surviving clock in England”. – Wikipedia

Photo: The clock face of world's oldest continually-working mechanical clock is seen as it is hand wound for the very last time on August 21, 2010 in Wells, England. (Photo by Matt Cardy/Getty Images)

“Hippo Chase”. As we approached the camp the Selinda Reserve of northern Botswana our boat passed by a hippo resting in the water. I turned around to look back at the boat's wake and saw the hippo charging after us! The hippo must've been tired from an all-nighter because he was angry. He rose way up out of the water three times trying to chase our boat! He was coming at us with such force that he created a wake of his own. Photo location: Selinda Reserve of northern Botswana. (Photo and caption by Curtis Simmons/National Geographic Photo Contest)

Shepherds lead their sheep through the centre of Madrid, Spain, Sunday, October 25, 2015. Shepherds have guided a flock of 2,000 sheep through Madrid streets in defense of ancient grazing, droving and migration rights increasingly threatened by urban sprawl and modern agricultural practices. Tourists and city-dwellers were surprised to see the capital's traffic cut to permit the ovine parade to bleat bells clanking its way past the city's most emblematic locations. (Photo by Daniel Ochoa de Olza/AP Photo)

These images show off some of the world's most majestic creatures silhouetted against the beautiful rising and setting sun. The vibrant pictures feature a variety of animals in the wild and were taken by a host of photographers at locations around the world. The striking images all have one thing in common: the photographers' awe-inspiring ability to perfectly capture the silhouettes of earth's beautiful creatures. Here: a blue wildebeest moves through grassland at dawn with the sun in the background in Mara Naboisho Conservancy, Kenya, Africa. (Photo by Renato Granieri/Caters News/Ardea)

Deputy community chief of Yeneka village Douglas Oguta poses for a portrait in his home on the outskirts of the Bayelsa state capital, Yenagoa, in Nigeria's delta region October 8, 2015. Tensions are building in the swampland of the Niger Delta as an amnesty that aimed to bring stability to Nigeria's volatile southern region is due to expire at the end of the year. While the region's towns and cities are mostly calm, local residents say kidnappings and armed robberies are on the increase in the mangrove swamps, where most oil wells are located. (Photo by Akintunde Akinleye/Reuters)

Located in Kunshan, eastern China, the restaurant relies on over a dozen machines for tasks such as greeting customers, waiting on tables and cooking basic meals. The eatery becomes the third café in the world to rely on the use of robot employees, potentially giving a glimpse into how future businesses could operate. Photo: This photo taken on August 13, 2014, shows a robot carrying food to customers in a restaurant in Kunshan. It's more teatime than Terminator – a restaurant in China is electrifying customers by using more than a dozen robots to cook and deliver food. (Photo by Johannes Eisele/AFP Photo)

As you look at the majestic Crater Lake, located in south-central Oregon, United States, it is hard to imagine that thousands of years ago this place was one giant crater with scorching hot lava spilling over the sides. Those were the times of turmoil. Now, however, this place is the essence of tranquility. The lake that was formed, after the volcano died down, is amazingly clear due to the fact that the water isn’t moving at all. No rivers go in or out of the Crater Lake, and the water lost through evaporation is compensated by the rain and snowfall. This lake is also frighteningly deep – 1,943 feet (592 m) at its deepest point – making it the deepest lake in the United States. If you love nature and if you ever come to Oregon, this is truly a sight to behold.

A tunnel with electric switches are seen in Josip Broz Tito's underground secret bunker (ARK) in Konjic, October 16, 2014. In the early 1950s, Josip Broz Tito, the late leader of the former Yugoslavia, ordered the building of the secret bunker, located 900 feet (270 m) underground and near the Bosnian town of Konjic, to safeguard the country's ruling class in case of a nuclear attack. Construction at the complex, which had a cost equivalent price tag of $4.6 billion, continued until 1979, the year before Tito died. (Photo by Dado Ruvic/Reuters)