Over the years a large population of grey herons have made an unlikely home in urban Amsterdam. Julie Hrudova documents how the birds integrate into city life. Here: Hundreds of herons come to the city during winter to find food and shelter. (Photo by by Julie Hrudova/The Guardian)

The Historic Photographer of the Year awards celebrate historic places and cultural sites across the globe, from national treasures to hidden gems. Entries were judged on originality, composition and technical proficiency as well as the story that inspired the submission and its historical impact. Here: Overall winner. Mont Saint-Michel by Daniel Burton. (Photo by Daniel Burton/The Guardian)

A devotee offers oil lamps on top of his body as part of a ritual during Dashain, the biggest religious festival for Hindus in Bhaktapur, Nepal, October 22, 2015. Hindus in Nepal celebrate victory over evil during the festival by flying kites, feasting, playing swings, sacrificing animals and worshipping the Goddess Durga as well as other gods and goddess as part of celebrations held throughout the country. (Photo by Navesh Chitrakar/Reuters)

“DC3 Wreck”. A capture of a US military DC3 plane wreck at the southern black beach in Iceland. Photo location: Iceland. (Photo and caption by Naian Feng/National Geographic Photo Contest)

There is an endless bounty of eye-catching gemstones throughout the world and this spectacular boulder opal is one unique beauty that looks like a shimmering crystal encased in a tree fossil. Its opalescent sheen seeps through the cracks of the seemingly wooden rings in lustrous hues of emerald green and aqua blue. Like something out of a fairy tale, the triangular piece radiates through an organic pattern mimicking the growth rings of tree.

Selfie picture shows Swiss pioneer Bertrand Piccard during the last leg of the round the world trip with Solar Impulse 2 over the Arab peninsula July 25, 2016. (Photo by Jean Revillard/Bertrand Piccard/Reuters/SI2)

In Omdurman, the largest city in Sudan, the Qadiriyya Sufi order meets every Friday outside Sheikh Hamed Al Nil mosque, which houses the tomb of their 19th century Sufi leader. (Photo by Ala Kheir, John Burns and Ibrahim Algrefwi/Brownbook)

Indian policewomen perform a stunt on their motorbikes during the full-dress rehearsal ahead of India's Independence Day celebrations in Srinagar, August 13, 2016. (Photo by Danish Ismail/Reuters)