Rare images of wild tigers in Bhutan, captured by camera traps, show tigers and other animals using high-altitude wildlife corridors which are lifelines to isolated tiger populations and critical to genetic diversity, conservation and growth. Here: A wild Bengal tiger (Panthera tigris tigris) captured on a camera trap in corridor eight at an altitude of 3,540 metres in Trongsa, Bhutan. (Photo by Emmanuel Rondeau/WWF UK/The Guardian)

In this August 31, 2017, photo, mock fish are displayed to offer to the ancestors during the “Hungry Ghost Festival” in Hong Kong. Countless hungry and restless ghosts are roaming Hong Kong, and the world, to visit their living ancestors, at least according to Chinese convention. In traditional Chinese belief, the seventh month of the lunar year is reserved for the Hungry Ghost festival, or Yu Lan, a raucous celebration marked by feasts and music. (Photo by Kin Cheung/AP Photo)

These frozen caves seem almost otherworldly as they daylight illuminates them. Matej Kriz’s shots reveal the beauty of the brilliant caves, but he’s also very aware of how deadly they can be. The photographer captured the amazing shots in the Vatnajokull National Park on the Breidamerkurjokull glacier tongue. Here: The ice caves, taken in the Vatnajokull National Park in Iceland, on November 11, 2017. (Photo by Matej Kriz/Caters News Agency)

Blacksmith Johann Schmidberger works on a suit of armour for the Vatican's Swiss Guards at his workshop in Molln, Austria, March 29, 2017. Austrian blacksmiths who produce ceremonial suits of armour for the Vatican's Swiss Guards are close to the end of their current deal to do so, and say supplying the suits will not now be an issue for many years to come. One of the drawbacks of the Swiss Guards' medieval uniforms is that the craftsmanship needed to make them is disappearing. (Photo by Leonhard Foeger/Reuters)

A man sits waiting for a train on the London Underground in 1890, when the platform floors were still made from wooden floorboards. (Photo by Hi-Story/Alamy Stock Photo)

Two Bunny Girls from the Playboy Club and two Penthouse Pets from the Penthouse Club prepare to take part in the annual Good Friday waiters and waitresses race in Battersea Festival Gardens, London, 28th March 1972. (Photo by Ian Showell/Keystone/Hulton Archive/Getty Images)

A boy tumbles as he plays soccer on the streets of the Khayelitsha township in Cape Town, December 3, 2009. (Photo by Kai Pfaffenbach/Reuters)

Jazmin, 6, sister of Jose Luis, receives Isoniazid Preventive Therapy in Carabayllo in Lima, Peru July 14, 2016. At least 30,000 Peruvians are infected with tuberculosis, an ancient disease that killed 1.8 million globally last year, more than AIDS-related and malaria deaths combined. Partners in Health, a Boston-based non-profit that works with Peru's health ministry, offers a simple solution. It trains community volunteers to tend to tuberculosis sufferers in their homes – ensuring patients take medicine daily and helping them navigate the public health bureaucracy. (Photo by Mariana Bazo/Reuters)