Busan, South Korea's second-largest city

cauldron

to take drastic measures to deal with a situation

lit. to break the cauldrons and sink the boats (idiom); fig. to cut off one's means of retreat

pressure chamber

to describe people in power that are only mediocre

to be like fish swimming in a cooking pot -- in imminent peril

a fish at the bottom of the pot (idiom)

burn your bridges behind you

lit. earthern pots make more noise than classical bells