The remnants of Jumbo, a large 214 tons steel container whose remnants lie in Trinity Site's parking lot.

It was originally designed as a fall-back to keep plutonium from spreading across the countryside, in case the high explosives successfully triggered but the nuclear process did not.

It was decided not to use Jumbo for the Trinity test. Already on-site, it was hung from a 70 feet tower 800 yards from ground zero. The tower was obliterated but Jumbo survived intact.

For unclear reasons, in 1946 the Army loaded several large bombs into Jumbo and detonated it, blowing off both end caps. They then buried the container, only for it to be excavated a few years later when the Trinity Site open houses started.