Kieron Connolly’s new book of photographs of more than 100 once-busy and often elegant buildings gives an idea of how the world might look if humankind disappeared. Here: Bodie, Mono County, California. Gold was discovered at Bodie in 1859 (just after the initial California gold rush) and it went from mining camp to boomtown. Its decline began in 1880, when word spread of new boomtowns elsewhere. The Standard Consolidated Mine closed in 1913, and four years later the Bodie Railway was abandoned. By 1940 the population was down to 40. Today, Bodie is maintained in a state of arrested decay as a visitor attraction. (Photo by Alamy Stock Photo)

“Environmental Migrants: The Last Illusion” by photographer Alessandro Grassani, documents the life of people in Kenya, Mongolia and Bangladesh who migrate to escape environmental stresses to the city of their own countries in hopes for a better life. Here: Asia, Mongolia, March 27, 2011. A view of Ulaan Baator over the shoulder of a slumbering drunk. Alcoholism is a huge problem in the city, home to almost half of Mongolia's people. The capital's population has doubled in the past two years. High levels of unemployment and poverty await herders who abandon rural areas and arrive in the city, illiterate and untrained in any skills necessary for urban jobs. (Photo by Alessandro Grassani)

A Nepalese Hindu devotee bathes in the Bagmati River on her way to the Pashupatinath Temple to offer prayers to Lord Shiva, Hindu god of destruction during Shravan festivities in Sundarijal, on the outskirts of Kathmandu on August 3, 2015. According to the Nepali calendar, Shravan is considered the holiest month of the year with each Monday of the month known as Shravan Somvar when worshippers offer prayers for a happy and prosperous life. (Photo by Prakash Mathema/AFP Photo)

A handout photograph provided by Brian Kubicki of Costa Rican Amphibian Research Center on 26 April 2016 shows a “Crystal frog”, Hyalinobatrachium dianae (H. diane). This frog was discovered by US biologist Brian Kubicki and Costa Ricans Stanley Salazar and Robert Puschendorf in a rainy forest of Costa Rican caribbean after 40 years without notice of any new example of this kind. (Photo by Brian Kubicki/EPA/Costa Rican Amphibian Research Center)

This picture taken on September 3, 2014 shows a man taking pictures of floodwater released from the Three Gorges Dam, a gigantic hydropower project on the Yangtze river, in Yichang, central China's Hubei province, after heavy downpours in the upper reaches of the dam caused the highest flood peak of the year. Eleven people died and 27 others are missing after torrential rains battered southwest China's Chongqing, a municipality in the upper reaches of the Three Gorges Dam, causing thousands of houses to collapse, state media said. (Photo by AFP Photo/Stringer)

Star trails form over the Memorial House of the Bulgarian Communist Party on mount Buzludzha in this long exposure picture taken on September 12, 2014. The monument was officially opened in 1981 by the Bulgarian Communist regime to mark 100 years of the set up of an organised Socialist movement, a predecessor of the Bulgarian Communist Party. The monument, no longer maintained by the Bulgarian government after the fall of the Communist regime in 1989, is now abandoned and vandalized. (Photo by Stoyan Nenov/Reuters)

Rowers enter in Canaregio river during the 42nd Venice Vogalonga on May 15, 2016 in Venice, Italy. 42 years ago a group of Venetians, both amateur and professional rowers, came up with an idea of non-competitive race in which any kind of rowing boat can take part. The first Vogalonga began with the message to protest against the growing use of powerboats in Venice and the swell damage they do to the historic city. (Photo by Awakening/Getty Images)

An Indian white tiger cools off in a pond in its enclosure at Chhat Bir Zoo on the outskirts of Chandigarh on May 22, 2016. Temperatures have soared to a scorching 51 degrees Celsius in one Indian city, meteorologists said, with the ferocious heat setting a new national record. Northern Phalodi wilted as the mercury reached a new high on May 20, equivalent to 123.8 Fahrenheit, beating a 60-year-old record. (Photo by Shammi Mehra/AFP Photo)