noun
telegraph office
A facility for sending and receiving telegrams. Now largely historical, as telegraph services have been discontinued in many countries.
昔はこの町にも電信局があった。
There used to be a telegraph office in this town as well.
郵便局 is a post office, which may have historically handled telegrams, but 電信局 specifically refers to a telegraph office.
Compound of 電信 (telegraph) and 局 (office, bureau).