▁the ▁occup ants ▁so ▁that ▁they ▁can ▁sum mon ▁help ▁using ▁a ▁mobile ▁or ▁land - line ▁phone . ▁Do ors ▁and ▁walls ▁can ▁be ▁rein for ced ▁with ▁steel , ▁Ke v lar , ▁sound - proof ▁or ▁bullet - res istant ▁fi berg lass ▁pan els . ▁The ▁door ▁to ▁the ▁safe ▁room ▁can ▁be ▁hidden ▁by ▁covering ▁it ▁with ▁pan els ▁that ▁match ▁existing ▁walls ▁or ▁doors ▁in ▁the ▁home . ▁ ▁M yth ological ▁and ▁fict ional ▁uses ▁ ▁Secret ▁pass ages ▁are ▁used ▁as ▁a ▁plot ▁element ▁or ▁as ▁part ▁of ▁the ▁setting ▁in ▁myth ological ▁stories , ▁fiction , ▁and ▁in ▁television ▁programs ▁or ▁films . ▁Secret ▁pass ages ▁in ▁old ▁buildings , ▁cast les , ▁ha unted ▁houses , ▁and ▁the ▁la irs ▁of ▁villa ins ▁or ▁super h ero es ▁enable ▁characters ▁to ▁secret ly ▁enter ▁or ▁exit ▁the ▁building , ▁access ▁a ▁hidden ▁part ▁of ▁the ▁structure , ▁or ▁enter ▁a ▁super natural ▁real m . ▁ ▁These ▁passage ways ▁are ▁often ▁opened ▁by ▁pulling ▁a ▁dis gu ised ▁lever ▁or ▁lock ▁mechanism . ▁In ▁some ▁cases , ▁a ▁certain ▁book ▁on ▁a ▁book sh elf ▁serves ▁as ▁the ▁hidden ▁trigger ▁for ▁the ▁mechanism . ▁ ▁M yth ological ▁uses ▁In ▁Greek ▁myth ology , ▁Hy rie us , ▁the ▁King ▁of ▁Bo e ot ia , ▁h ired ▁Tro phon ius ▁and ▁Ag amed es ▁to ▁build ▁a ▁tre asure ▁chamber ▁for ▁him . ▁However , ▁the ▁pair ▁built ▁in ▁a ▁secret ▁entrance