Beneath the Swedish capital lies an intricate web of underground train lines. More than 90 of the 100 stations in the 110km tunnel system, sometimes referred to as “the world’s longest art gallery”, have been decorated with paintings, installations, mosaics and sculptures by 150 artists since the 1950s. After spending a couple of weeks exploring arctic Norway and Sweden, London-based travel photographer Conor MacNeill headed underground to capture images of the metro stations. Here: A rainbow arcs over a girl on the platform of Stadion station. (Photo by Conor MacNeill/The Observer)

Filippo Negroli (ca. 1510–1579) was an armourer from Milan. He was renowned as being extremely skilled, and may be considered the most famous armourer of all time. Working together with his younger brothers Giovan Battista (ca. 1511-1591) and Francesco (ca. 1522-1600) in the Negroli family workshop headed by their father Gian Giacomo Negroli (ca. 1463-1543), Filippo was specialized in repoussé of armour, whereas his brother Francesco was renowned for his damascening skills.

Founded in 1989, the Icehotel in Swedish Lapland is built from the snow up each year, using ice from the local river. The rooms are designed by international artists and this year feature spacemen and an ice queen. The hotel has 35 suites, featuring ice carvings designed by 36 different artists from 17 countries. (Photo by Asaf Kliger/IceHotel/The Guardian)

“Li Wei (born in 1970, Hubei, China) is a contemporary artist from Beijing, China. His work often depicts him in apparently gravity-defying situations. Wei started off his performance series, Mirroring, and later on took off attention with his Falls series which shows the artist with his head and chest embedded into the ground. His work is a mixture of performance art and photography that creates illusions of a sometimes dangerous reality. Li Wei states that these images are not computer montages and works with the help of props such as mirror, metal wires, scaffolding and acrobatics”. – Wikipedia

Photo: Love at the high place I (Photo by Li Wei)

A white-skinned Indian couple are set to enter the record books along with their offspring, after becoming the world's biggest albino family. The ten members of the Pullan family, headed by Rosetauri, 50, and his wife Mani, 45, all have the extremely pale skin and near-white hair of albinos.But despite years of prejudice and suffering the poor vision which is a side effect of the condition, the Pullans and their eight other family members are set to land a Guinness World Record.

Head of European Prints, Severine Nackers holds a celestial Map of the Southern Sky by Albrecht Durer, at Sotheby's Auction House on March 25, 2011 in London, England. The two woodcut maps depicting the Northern and Southern skies circa 1515, are the earliest printed star charts of their kind ever published in Europe, and are expected to fetch between Ј120,000-180,000 GBP when they go on sale at the “London sale of Old Master, Modern and Contemporary prints” at Sotheby's Auction house on March 30, 2011. (Photo by Dan Kitwood/Getty Images)

Ucil, a trained monkey, takes part in a street performance on June 1, 2011 in Jakarta, Indonesia. The street performances usually involve the monkeys wearing masks, such as dolls' heads or attire to mimic humans, with the monkeys trained to act out human activities such as shopping, riding bicycles or other simulations of human behaviour. Poverty drives the handlers to exploit the monkeys in the hope of earning small change, but the effect and cruelty to the monkeys is a cause that charities such as the Jakarta Animal Aid Network are increasingly taking up. (Photo by Ulet Ifansasti/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)