Haley Nordeen, 19, is spending the entire summer at the Prodesenh center in San Mateo Milpas Altas, Guatemala. The American University student helped build the center's new library. Carrie Kahn/NPR hide caption

itoggle caption Carrie Kahn/NPR

Fishermen drag a net in Lake Malawi in 2012. About the size of New Jersey, the lake is home to hundreds of fish species and is considered one of the most biologically diverse lakes in the world. Ding Haitao/Xinhua/Landov hide caption

itoggle caption Ding Haitao/Xinhua/Landov

A boy collects water at a new spigot in Shululu, Tajikistan. Before the government built a new water system, villagers were allocated half-hour time slots to collect water from a trickling tap. Jason Beaubien/NPR hide caption

itoggle caption Jason Beaubien/NPR

The city of Sao Paolo, Brazil, shot with a fisheye lens. Standards of living are improving not just in the big developing nations like Brazil, but also in smaller countries such as Bangladesh and Ghana. Daniel Incandela/Flickr via Wikimedia Commons hide caption

itoggle caption Daniel Incandela/Flickr via Wikimedia Commons

Many homes that were rebuilt after the earthquake in 2010 are even more dangerous than the original ones. This three-story home was put up after the quake but is already slated for demolition to make way for an 18-unit housing project. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR

Ayo Bello grabs a box of malaria medication at a pharmacy in Lagos, Nigeria. A pilot project by the Global Fund has helped private pharmacies and clinics sell top quality malaria drugs at wholesale prices in Nigeria and seven other African countries. Sunday Alamba/Associated Press hide caption

itoggle caption Sunday Alamba/Associated Press