The British monitors were basically destroyer sized ships with a single battleship turret mounted on them. (2 15” guns). They had two left over from WWI (one lost off north Africa) and built another 2 in WWII. While one of the new ones was to be deployed to the Pacific, it didn’t reach the theater before the end of the war.
I believe they used a monitor to sink this ship(click on link at page):
https://en.wikipedia.org/wiki/SMS_K%C3%B6nigsberg_(1905)
There is a great book about it.