Construction continues on One World Trade Center (TALLEST BUILDING AT LOWER LEFT) as the memorial footprints of the twin towers are seen (BOTTOM C) on August 12, 2011 in New York City. Upon completion, One World Trade Center will be New York's tallest skyscraper, topping out at a symbolic 1,776 feet, with 3 million square feet of office space. More than 2,700 people were killed when al-Qaeda terrorists hijacked U.S. passenger jets and flew them into the twin towers of the World Trade Center on September 11, 2001. Nearly ten years after the crippling attacks on Lower Manhattan, business, tourism and new construction like One World Trade Center have rejuvenated the formerly devastated cityscape.(Photo by Mario Tama/Getty Images)

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)

With more than 40,000 followers on Twitter and 26,400 fans on Vine, it looks like Marutaro the hedgehog from Japan is one of the most popular hedgehogs on the Internet. And as his owner keeps on posting Marutaro’s pictures online daily, Marutaro’s popularity continues to grow. There are hundreds of cute photographs and videos of this little fellow, but the ones with little paper cut-out faces are probably the cutest. As Marutaro lies on his back, his owner gives him a variety of silly expressions and smiles. The 20 best of them will definitely boost your mood!

A model poses beside the Porsche Hybrid during the media day of the Shanghai International Automobile Industry Exhibition at Shanghai New International Expo Center on April 19, 2011 in Shanghai, China. The 14th Shanghai International Automobile Industry Exhibition (Auto Shanghai 2011) will be held from April 21 to 28 with the theme of “Innovation For Tomorrow”. About 2,000 carmakers and parts providers from 20 countries are due to showcase 1,100 car models, 75 of which makes their world premieres in the auto show. (Photo by Feng Li/Getty Images)

“Horst Ludwig Wessel (October 9, 1907 – February 23, 1930) was a German Nazi activist who was made a posthumous hero of the Nazi movement following his violent death in 1930. He was the author of the lyrics to the song “Die Fahne hoch” (“The Flag On High”), usually known as Horst-Wessel-Lied (“The Horst Wessel Song”), which became the Nazi Party anthem and, de facto, Germany's co-national anthem from 1933 to 1945”. – Wikipedia

Photo: German Nazi activist Horst Wessel (left) at the head of a parade of S.A. stormtroopers, or “brownshirts”, in Nuremberg, Germany, 1929. (Photo by Hulton Archive/Getty Images)

“Huangguoshu Waterfall, also known as Yellow Fruit Tree Waterfall, is one of the largest waterfalls in China and East Asia located on the Baihe River in Anshun, Guizhou Province. It is 77.8 m (255 ft) high and 101 m (331 ft) wide. The main waterfall is 67 m (220 ft) high and 83.3 m (273 ft) wide”. – Wikipedia

Photo: The Miao ethnic minority women rest in front of Huangguoshu Cataract, Asia's largest waterfall, on September 13, 2011 in Anshun city of Guizhou Province, China. (Photo by Feng Li/Getty Images)

Hostesses pose for photos with a police officer on the motorized vehicle during the third plenary meeting of the 11th National Committee of the Chinese People's Political Consultative Conference (CPPCC) at The Great Hall Of The People on March 10, 2012 in Beijing, China. (Photo by Feng Li/Getty Images)