ALBUQUERQUE, N.M. >> Los Alamos, a once secret city where scientists participated in the nation’s classified World War II nuclear development program, can now be experienced much like it was then with a new app.

The “Los Alamos: The Secret City of The Manhattan Project” iPhone app takes users through an “augmented-reality” while visiting the northern New Mexico city to see it in its 1940s character. The app was created by Los Alamos National Laboratory.

Packed with games, historical nuggets and role playing, the app allows users to feel what it was like to join a secret project in an unknown location where the future of the world was at stake, said Jennifer Payne, Resource Management Team leader in Los Alamos’ Environmental Stewardship Group. Because Los Alamos has changed since the project and is now a modern city, Payne said the app takes users on a virtual tour of a Manhattan Project world that is gone.

“It took us more than a year to create,” Payne said. “Almost all of the structures from that era don’t exist anymore.”

Once downloaded and opened, users will receive a “recruitment telegram” to begin the virtual journey from 109 E. Palace Ave., in Santa Fe. That’s the same location where the original Project Y staff members joined the team. Users then will receive an initial “clearance” there, then board a bus into the mountains to explore “the Hill.”

From there, Payne said users can choose how much information they want to know while they explore Los Alamos as the bomb is developed.

Of course, no actual nuclear secrets are shared, she said.

Officials said the project is a collaboration of Los Alamos National Laboratory’s VISIBLE team, the Bradbury Science Museum, and staff history specialists.

Developers also are working on an Android app.

During World War II, Los Alamos scientists worked to develop the atomic bomb that was dropped on the Japanese cities of Hiroshima and Nagasaki. The secret program provided enriched uranium for the atomic bomb. It also involved facilities in Oak Ridge, Tennessee, and Hanford, Washington.

July marks the 71st anniversary of the Trinity Test in southern New Mexico. The milestone comes amid renewed interest in the Manhattan Project thanks to new books, online video testimonies and the recently canceled TV drama series “Manhattan.”