It was detonated on 26 March 1954, at Bikini Atoll of the Marshall Islands, on a barge moored in the middle of the crater from the Castle Bravo test.

It often serves as a stand-in for nuclear weapons in general for news stories, book covers, magazine articles, etc., likely because of its threatening appearance and extreme red, orange, and yellow hues.

One prominent usage is as the backdrop for American thrash metal band Megadeth's compilation album Greatest Hits: Back to the Start, released in 2005.

The image of Castle Romeo was also used on the cover of the New York hardcore music pioneers Cro-Mags debut studio album The Age of Quarrel in 1986.

The two nuclear blasts looked very similar, and they were both conducted in the same location, but much of Bravo's photographic record was destroyed because of its unexpectedly high yield.