郵便局 (yūbinkyoku) means “post office”

More examples

今日は郵便局で切手を買います。kyō wa yū bin kyoku de kitte o ka i ma su

Today I buy stamps at the post office.

祖母に荷物を送るため、郵便局へ行きます。so bo ni ni motsu o oku ru ta me yū bin kyoku e i ki ma su

I go to the post office to send a package to my grandmother.

A place where mail is accepted, processed, and sent, often along with related public services.

郵便局に行くyū bin kyoku ni i ku
go to the post office
郵便局から荷物を送るyū bin kyoku ka ra ni motsu o oku ru
send a package from the post office

局kyoku: A local office for postal services, with the shorter name used when the type of office is clear.

手紙や荷物の引き受け、配達などを行う施設。te gami ya ni motsu no hi ki u ke hai tatsu na do o okona u shi setsu

郵便局 (yūbinkyoku) combines 郵 (yū, "postal service"), 便 (bin, "mail"), and 局 (kyoku, "office or bureau") in a Sino-Japanese compound.

In Japan, many 郵便局 (yūbinkyoku) provide banking and insurance services as well as handling mail, so the word can refer to more than a place for letters.