A replica of pre-historic drawings showing horses, rhinoceros and aurochs is seen on a wall during a press visit at the site of the Cavern of Pont-d'Arc project in Vallon Pont d'Arc April 8, 2015. The Cavern of Pont-d'Arc project is a replica of the pre-historic Decorated Cave of Pont-d'Arc known as Grotte Chauvet, in Vallon Pont-d'Arc in the Ardeche region, containing the world's earliest known art which was recently named a UNESCO World Heritage site. The facsimile cavern, which condenses some 8000m² of the original site into 3000m², will display faithful reproductions of paintings and engravings and will be inaugurated on April 10 and will open to the public on April 25. (Photo by Robert Pratta/Reuters)

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)

Individuals brave the freezing temparature in Combs reservoir as they take part in a cold water therapy treatment near Chapel en le Frith, northwest England on January 1, 2021. (Photo by Oli Scarff/AFP Photo)

Bystanders look on as workers arrange silver blue fabric, part of the process of wrapping L'Arc de Triomphe in Paris on September 13, 2021, designed by the late artist Christo. Work has begun on wrapping the Arc de Triomphe in Paris in silvery-blue fabric as a posthumous tribute to the artist Christo, who had dreamt of the project for decades. Bulgarian-born Christo, a longtime Paris resident, had plans for sheathing the imposing war memorial at the top of the Champs-Elysees while renting an apartment near it in the 1960s (Photo by Geoffroy Van der Hasselt/AFP Photo)

(2nd from R) Miss Georgia Betty Cantrell reacts to advancing, en route to victory, at the Miss America Pageant at Boardwalk Hall, in Atlantic City, New Jersey, September 13, 2015. (Photo by Mark Makela/Reuters)

Shiite Muslim pilgrims march with flags en route to Karbala from Nasiriyah in Iraq's southern Dhi Qar province on September 5, 2022, ahead of the holiday of Arbaeen. (Photo by Asaad Niazi/AFP Photo)

View of a light show on the city's iconic Arc de Triomphe monument during the New Year celebration in Paris, France, December 31, 2016. (Photo by Jacky Naegelen/Reuters)

Protesters a demonstration of the LGTBI collective in Madrid on November 20, 2021 against the rise of the fascism in the society and in support of the new transgender law in Spain. (Photo by Celestino Arce Lavin/ZUMA Press Wire/Rex Features/Shutterstock)