blue chamber

idiomatic

(idiomatic) A forbidden room.

Japanese Meaning

禁断の部屋

They warned us never to enter the blue chamber, but curiosity got the better of me.

彼らは私たちに決して禁じられた部屋に入るなと警告したが、好奇心に負けてしまった。

Sense（1）

(idiomatic) A forbidden room.

[…] Matty would scarcely find fault with my visiting their blue chamber. […]

blue chambers

（ plural ）