A tour group wanders through block 7 of Eastern State Penitentiary in Philadelphia, Pennsylvania April 30, 2014. Opened in 1829, with the original corrective system of “confinement in solitude with labor”, the penitentiary housed about 75,000 inmates in its 142 years of operation. At Eastern State reunions, former inmates, staff and guard gather to share memories and trade stories and get a chance to describe their experiences in question-and-answer sessions with the public. (Photo by Mark Makela/Reuters)

Cuban girls dressed as nurses and a lizard wait for their turn to dance during a visit by the Gay Men's Chorus of Washington in Havana July 13, 2015. The choir made its first appearance on July 12, 2015 in Cuba as part of a tour that will include a dozen concerts in the context of the restoration of relations between the island and the United States. (Photo by Enrique de la Osa/Reuters)

Rwandan refugees cross the Rusumo border to Tanzania from Rwanda carrying their belongings, goats, mattresses and cows, May 30, 1994. The bloodshed that claimed 800,000 Tutsi and moderate Hutu lives began 25 years ago on April 7, 1994, when a plane carrying Rwandan President Juvenal Habyarimana, Burundi President Cyprien Ntaryamira and a French air crew was shot down. (Photo by Jeremiah Kamau/Reuters)

A Palestinian female masked militant from the Al-Quds Brigades, the military wing of the Islamic Jihad, takes part in an Islamic Jihad rally in Rafah, southern Gaza Strip, 29 July 2016. (Photo by Mohammed Saber/EPA)

Jockey student Mariangelys Almedina (Front) balances on a steel drum suspended in the air by a series of springs to simulate riding a horse as Instructor Willie Lozano looks on at the Vocational Equestrian Agustín Mercado Reverón School located in the Hipódromo Camarero on November 17, 2022 in Canovanas, Puerto Rico. The Vocational Equestrian Agustín Mercado Reverón School has produced some of the best jockeys in the world but also prepares students for a wide range of equestrian jobs on a tuition-free basis. (Photo by Al Bello/Getty Images)

Dema and Manis, the 26-day-old endangered Sumatran Tiger cubs play together at the “Taman Safari Indonesia” Animal Hospital, on February 26, 2007 in Cisarua, Bogor Regency, West Java, Indonesia. The two Sumatran tiger-cubs recently born at the hospital have been rejected by their mother Cicis, while baby Orangutans, Irma and Nia have also been rejected by their mothers. All babies are being looked after by staff at the Animal Hospital. (Photo by: Dimas Ardian/Getty Images)

Mud-covered tourists pretend to be trapped inside a mud prison at the Daecheon Beach Mud Plaza in the city of Boryeong on South Korea's west coast, July 17, as they take part in the Boryeong Mud Festival, which opened that day and runs through July 26. Boryeong mud is rich in natural mineral component and is considered to prevent skin aging. (Photo by EPA/Yonhap)

A prisoner from the Pedrinhas prison is carried to receive medical help after he was injured during a fight between rival gangs inside the jail, in Sao Luiz, capital of Maranhao state, January 8, 2014. The recent posting on a major Brazilian news website of a video filmed last December 17 by Pedrinhas prisoners of the decapitated and tortured bodies of rival inmates inside the jail has highlighted some of the problems present in the country's prison system which houses nearly twice as many prisoners as its capacity, according to official statistics. (Photo by Douglas Cunha/Reuters/O Estado do Maranhão)