Quick Answers Table

Question	Short Answer	Detail
Did an angel visibly appear?	Traditional legend	590 plague narrative; later chroniclers amplify
Are there secret tunnels everywhere?	Limited documented passages	Primarily Passetto + service corridors
Full Passetto walk feasible?	Not freely	Guided short segments only
Imperial ashes still present?	Displaced / lost	Spoliation & medieval upheavals
Prison torture chambers extensive?	Exaggerated	Confinement yes; dramatized tales inflated

Myth Busting

Endless hidden tunnels: Structural practicality + river proximity limit proliferation.
Angel sighting fully documented contemporaneously: Survives mostly as later narrative reinforcement.
Intact mausoleum burial sequence: Fragmentary; research relies on archaeology & textual inference.

Length ~800 m historically linking Vatican precinct; elevated defensive logic rather than secret escape only—symbol of papal protective network.

Ask staff about current special corridor access dates.
Look for masonry differences showing era transitions (Hadrianic core vs Renaissance facing).

Separating evocative legend from architectural fact deepens appreciation—you witness a palimpsest, not a frozen myth tableau.