Ursula Sprecher and Andi Cortellini are obsessed with people’s hobbies. The two Swiss artists have spent the past seven years traveling across their native Switzerland photographing gatherings of like-minded people in a myriad array of interests and niche groups.

Lake Baikal is the world's oldest lake, at 25 million years (possibly older), and deepest, averaging 744.4 metres (2,442 ft).

Located in the south of the Russian region of Siberia, between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast, it is the most voluminous freshwater lake in the world, containing roughly 20% of the world's unfrozen surface fresh water.

Model enthusiast Peter Smith poses with his collection of handmade scale model coaches at the “London Model Engineering Exhibition” at Alexander Palace on January 20, 2012 in London, England. (Photo by Dan Kitwood/Getty Images)

Wanwisa, a Lao Yi Lai Heng Chinese opera performer waits backstage at the Plub Plachai temple on January 25, 2012 in Bangkok, Thailand. The traditional Chinese art form involving music, singing, martial arts and acting has a history of more than 500 years. There are about 30 members working with the group doing specials shows all week to celebrate the Chinese New year. The Chinese opera is popular in many parts of China, Malaysia, Singapore, Thailand and Macau. (Photo by Paula Bronstein/Getty Images)

A woman holds a parasol as she stands in a field of fireweed, or Kochia scoparia, on a sunny autumn day at the Hitachi Seaside Park in Hitachi, north of Tokyo, October 26, 2015. Fireweed is a grass bush that takes on a bright red colour in autumn. (Photo by Thomas Peter/Reuters)

People dressed in national clothes sing songs during the regional harvest festival in the town of Dyatlovo, Belarus, November 13, 2015. (Photo by Vasily Fedosenko/Reuters)

Underwater photographer Alexander Semenovs has snapped some of the most stunning, fragile life forms anywhere on planet Earth. Shot in deep, dark conditions, the images continue to provide an insight into what lies beneath, with glowing creatures appearing a lot like aliens in the pitch-black water. Semenovs has shot the likes of bioluminescent jellyfish, aggressive-looking worms and many species that leave a lot to the imagination. The 30-year-old from Moscow does the majority of his work in the White Sea, near the Arctic Circle. Here: A Comb jelly – Beroe cucumis. (Photo by Alexander Semenovs/Caters News)