Los Alamos National LaboratoryBradbury Science Museum
Your Window into Los Alamos National Laboratory
Bradbury Science Museum

The Manhattan Project National Historical Park

Preserving and sharing the nationally significant historic sites, stories, and legacies associated with the top-secret race to develop an atomic weapon during World War II.

January 10, 2022
1946 aerial view of Los Alamos

This photo, taken on December 4, 1946, shows the center of Los Alamos as it looked during Project Y years. Called Technical Area 1, it was the core of the original laboratory.

  • Manhattan Project NHP-Los Alamos Project Manager
  • Cheryl Abeyta
  • EPC-DO
  • Email

In 1943, as World War II raged across the globe, the United States government secretly constructed a laboratory on a group of isolated mesas in northern New Mexico. The top-secret Manhattan Project had a single military purposedevelop the world’s first atomic weapons.  

The success of this unprecedented government program forever changed the world. Join us to discover the stories of the people behind the Manhattan Project and how they shaped the world we live in today.

Project Y: A brief history

Scientists, engineers, explosive experts, military personnel, and members of the Special Engineer Detachment all convened on the rural Pajarito Plateau in New Mexico for a secret project during World War II. Their mission: develop an atomic weapon before Nazi Germany. General Leslie R. Groves selected J. Robert Oppenheimer, a theoretical physicist from the University of California at Berkeley, as the scientific project director. This unprecedented undertaking required revolutionary science, engineering, technological innovation, and collaboration between civilians and military personnel from diverse backgrounds.

Twenty-eight months after Project Y began in Los Alamos, members of the Manhattan Project detonated the world’s first atomic weapon, the "Gadget," at the Trinity Site in southern New Mexico. After the military deployment of two atomic weapons on the Japanese cities of Hiroshima and Nagasaki, and the subsequent end of World War II, some Los Alamos scientists took their families and returned to their pre-war lives. Yet, many stayed to continue critical research in this new Nuclear Age.

Today, Los Alamos National Laboratory remains one of the United States’ premier science and technology institutions. Cutting-edge research and technological breakthroughs still happen here, as scientists and engineers work to solve some of today’s most complex problems.

The Manhattan Project’s legacy of revolutionary science and engineering, along with the lessons learned from that time, continues in the spirit of the modern Laboratory. Scientific and technological advances made in the pursuit of an atomic weapon contributed to progress in many areas: environmental and materials science, biology, nuclear medicine, nuclear energy, supercomputing, precision machining, even astronomy. This was also the beginning of the Department of Energy’s National Laboratory System.

Establishment of the Park


The U.S. Congress directs the National Park Service and the Department of Energy to determine the significance, suitability, and feasibility of including signature facilities remaining from the Manhattan Project in a national historical park. This was an effort to preserve remaining structures in order to save them from being lost forever.  


The National Defense Authorization Act, signed by President Obama, authorizes the creation of Manhattan Project National Historical Park. The stated the purpose of the park is “to improve the understanding of the Manhattan Project and the legacy of the Manhattan Project through interpretation of the historic resources.” On November 10, 2015, a Memorandum of Agreement signed by the Secretary of the Interior and the Secretary of the Department of Energy makes the park a reality.


Three sites tell the story of more than 600,000 Americans working to help end World War II. These three locations, integral to the Manhattan Project, comprise the park today.

  • Project Y at Los Alamos, New Mexico designed and built the first atomic bombs. 
  • Site X at Oak Ridge, Tennessee enriched uranium needed for the gun-type fission weapon.  
  • Site W at Hanford, Washington created plutonium for an implosion-type weapon design.


The Manhattan Project National Historical Park encompasses 17 sites on Los Alamos National Laboratory property and 13 sites in downtown Los Alamos, where “Project Y” was centered during World War II. These sites represent the world-changing history of the Manhattan Project at Los Alamos.  

Today, you can visit the Los Alamos Downtown historic sites, but the sites on Laboratory land are not accessible to the public. However, the Department of Energy, Los Alamos National Laboratory, and the National Park Service collaborate to provide public tours of three sites on Laboratory property. Click here for more information on these tours and how to register for them.