Photographer Gregg Segal travelled the world to document children and the food they eat in a week. Partly inspired by the increasing problems of childhood obesity, he tracked traditional regional diets as yet unaffected by globalisation, and ironically, found that the healthiest diets were often eaten by the least well off. (Photo by Gregg Segal/The Guardian)

Runner-up. “The City of London, looking towards the Royal Exchange and the Bank of England. The ever-changing London skyline provides many excellent opportunities for cityscape photography, none more exciting than the ebb and flow of traffic at night”. (Photo by Mark Caldon/The Guardian)

How sure are you of your geographical knowledge? Buzzfeed recently put Americans’ geographical knowledge to the test with a survey in which participants had to write in countries’ names on a blank European political map. Unfortunately, they didn’t fare too well, but some of their responses are hilarious (or hilariously mis-informed). But don’t be so quick to judge Americans – when Buzzfeed posted a similar survey testing Brits’ knowledge of the 50 United States, they also came up short. On the one hand, knowing a country’s states is different from knowing independent countries, but on the other, some U.S. states are larger than some European nations, and some U.S. states have larger economies than some European nations.

Dan surrounded by seven days of her own rubbish in Pasadena, California. If you've never thought about how much rubbish you throw away an honest photographic series will open your eyes. Men, women, couples and families with young children have been photographed lying on their backs surrounded by a week's worth of their own rubbish – from old cartons of milk, used nappies and even tampons. The startling series “Seven Days of Garbage” by Californian photographer Gregg Segal is an unforgettable reminder of the amount of waste a human collects in just seven days. (Photo by Gregg Segal/Barcroft Media)

Few things are more beautiful than puffy white clouds floating in the bright blue sky. Do you remember the time when you would lay on the soft green grass, look up at the sky, and try to recognize shapes in the clouds floating overhead? Wasn’t it wonderful, just lying there, letting the wind caress your skin, as you imagine that the clouds in the sky are actually mystical or not-so-mystical creatures? Dragons, ducks, teddy bears, dinosaurs, everything was up there. It was good old times. As adults we forget about simple pleasures of life. However, an Argentinian artist Martin Feijoo didn’t forget those times, and took them a step further. After imagining what a particular cloud looks like, he draws that particular shape over the picture of the cloud, allowing the entire world to see what goes on in his mind. (Photo by Martin Feijoo)

With its huge eyes, comical name and diminutive size, Mark R. Smith’s image of a baby Hawaiian bobtail squid can’t help but raise a smile. A curiously endearing creature, the cephalopod is just 1.5cm across, its mantle cavity bearing more than a passing resemblance to a rather natty shower cap. But it is also a beautiful example of symbiosis – nature’s version of “I’ll scratch your back if you scratch mine” – for on the underside of the squid is a light organ which houses bioluminescent bacteria. The squid offers the bacteria protection and food, while the bacteria emit a glow – a handy trait that the squid uses to offset its silhouette, helping it to evade predators in the depths below. Mark R. Smith’s entry combines several images of a Hawaiian bobtail squid with different focus lengths to create a final picture with greater depth of field than normal. (Photo by Mark R. Smith/Wellcome Images/Macroscopic Solutions)

In the spring of 1965, within weeks of 3,500 American Marines arriving in Vietnam, a 39-year-old Briton named Larry Burrows began work on a feature for LIFE magazine, chronicling the day-to-day experience of U.S. troops on the ground – and in the air – in the midst of the rapidly widening war. The photographs in this gallery focus on a calamitous March 31, 1965, helicopter mission; Burrows’ “report from Da Nang”, featuring his pictures and his personal account of the harrowing operation, was published two weeks later as a now-famous cover story in the April 16, 1965, issue of LIFE.

Photo: Man your battle stations: The crew chief of helicopter Yankee Papa 13, lance corporal James C. Farley, mans an M-60 machine gun during a mission near Da Nang, Vietnam on March 31, 1965. (Photo by Larry Burrows/Time & Life Pictures)

When you first see the art works created by a Thai metalworker Ban Hun Lek, you are completely stunned by the level of detail of the metal sculptures that he creates. One of his most prominent creations is a full sized sculpture of a Hulk. The fact that this sculpture was created practically solely out of steel nuts adds to the rugged feeling of force that emanates from this creation. And if you think that this creation is amazing, you should look at his other works such as the Ganesha – the god of wisdom, knowledge and new beginnings, or the Predator. For that matter, almost every sculpture that he creates blows your mind away, making you wonder just how many hours has he put into making these amazing pieces of art. (Photo by BanHunLek)