Bastille

Festung

(fortified tower or other building)

Kerker

(jail or prison, especially one regarded as mistreating its prisoners — see also jail, prison)

einkerkern

(to confine (someone or something) in, or as if in, a bastille or prison — see also imprison)

gefangen halten

(to confine (someone or something) in, or as if in, a bastille or prison — see also imprison)