Apart from Carrie-Anne Moss, Trinity was the code name of the very first detonation of a nuclear device. The test involved an implosion-design plutonium device. The bomb had the name "The Gadget" and released energy equal to 20 kilotons of TNT. It was conducted by the United States Army on July 16, 1945 in the Jornada del Muerto desert about 35 miles southeast of Socorro, New Mexico. This date was the opening of a new era, the Atomic Age...
Eventually, this test lead to the Fat Man, the bomb with the same conceptual design that was detonated over Nagasaki, Japan, on August 9, 1945.
First Photo: The Trinity explosion, 16 ms after detonation. [Source: Wikipedia]
Second Photo: The Gadget. [Source: Wikipedia]