Pajarito Plateau in the context of "Volcanic plateau"

The Los Alamos Laboratory, also known as Project Y, was a secret scientific laboratory established by the Manhattan Project and overseen by the University of California during World War II. It was operated in partnership with the United States Army. Its mission was to design and build the first atomic bombs. J. Robert Oppenheimer was its first director, serving from 1943 to December 1945, when he was succeeded by Norris Bradbury. In order to enable scientists to freely discuss their work while preserving security, the laboratory was located on the isolated Pajarito Plateau in northern New Mexico. The wartime laboratory occupied buildings that had once been part of the Los Alamos Ranch School.

The development effort initially focused on a gun-type fission weapon using plutonium called Thin Man. In April 1944, the Los Alamos Laboratory determined that the rate of spontaneous fission in plutonium bred in a nuclear reactor was too great due to the presence of plutonium-240 and would cause a predetonation, a nuclear chain reaction before the core was fully assembled. Oppenheimer then reorganized the laboratory and orchestrated an all-out and ultimately successful effort on an alternative design proposed by John von Neumann, an implosion-type nuclear weapon, which was called Fat Man. A variant of the gun-type design known as Little Boy was developed using uranium-235.

Bandelier National Monument is a 33,677-acre (136 km) United States National Monument near Los Alamos in Sandoval and Los Alamos counties, New Mexico. The monument preserves the homes and territory of the Ancestral Puebloans of a later era in the Southwest. Most of the pueblo structures date to two eras, dating between AD 1150 and 1600.

The monument comprises 50 square miles (130 km) of the Pajarito Plateau, on the slopes of the Jemez volcanic field in the Jemez Mountains. Over 70% of the monument is wilderness, with over one mile of elevation change, from about 5,000 feet (1,500 m) along the Rio Grande to over 10,000 feet (3,000 m) at the peak of Cerro Grande on the rim of the Valles Caldera, providing for a wide range of life zones and wildlife habitats. 3 miles (5 km) of road and more than 70 miles (110 km) of hiking trails are built. The monument protects Ancestral Pueblo archeological sites, a diverse and scenic landscape, and the country's largest National Park Service Civilian Conservation Corps National Landmark District. Two-thirds of the park, 23,267 acres (9,416 ha), is designated as the Bandelier Wilderness Area. Motorized travel and permanent structures are forbidden in the Wilderness.

Los Alamos (Spanish: Los Álamos, meaning The Poplars) is a census-designated place in Los Alamos County, New Mexico, United States, that is recognized as one of the development and creation places of the atomic bomb—the primary objective of the Manhattan Project by Los Alamos National Laboratory during World War II. The town is on four mesas of the Pajarito Plateau, and had a population of about 13,200 as of 2020. It is the county seat and one of two population centers in Los Alamos County; the other is White Rock.