- B ish ops ▁until ▁ 1 8 0 3 . ▁U sed ▁by ▁the ▁Aust ri ans ▁as ▁military ▁bar ra cks ▁and , ▁later , ▁as ▁a ▁j ail , ▁it ▁decay ed . ▁In ▁the ▁ 1 9 2 0 s , ▁when ▁Tr ento ▁was ▁returned ▁to ▁Italy , ▁it ▁became ▁seat ▁of ▁a ▁National ▁Museum ▁and ▁was ▁restored . ▁Since ▁ 1 9 9 2 ▁it ▁is ▁home ▁to ▁the ▁Provin cial ▁Gallery ▁of ▁Art . ▁ ▁According ▁to ▁legend , ▁it ▁was ▁connected ▁by ▁a ▁secret ▁tunnel ▁to ▁the ▁city ' s ▁c athedral , ▁which ▁allowed ▁the ▁prince - b ish ops ▁to ▁move ▁un seen ▁between ▁them . ▁ ▁In ▁ 2 0 1 5 , ▁rights ▁were ▁granted ▁for ▁the ▁first ▁time ▁to ▁film ▁inside ▁the ▁castle , ▁for ▁Sebast iano ▁S era f ini ' s ▁music ▁video ▁for ▁his ▁single ▁" A k ane ". ▁ ▁Inter ior ▁ ▁The ▁interior ▁h alls ▁have ▁pre cious ▁fres co es , ▁including ▁those ▁in ▁the ▁Torre ▁Aqu ila ▁(" E agle ▁Tower "), ▁which ▁are ▁one ▁of ▁the ▁most ▁not ew orth y ▁examples ▁of ▁International ▁Goth ic ▁art ▁in ▁Europe : ▁they ▁represent ▁the ▁" C ycle ▁of ▁the ▁Month s " ▁( 1 5 th ▁century ) ▁ ▁and ▁were ▁made ▁by ▁an ▁unknown ▁artist ▁from ▁Boh emia . ▁The ▁cycle ▁is ▁interesting ▁also ▁for ▁its ▁accurate ▁port ray al ▁of ▁the ▁landscape , ▁the ▁economic ▁activities , ▁the ▁hab its