Examine the Street-Level Ventilation Window

Before or after heading underground, stop outside on Resslova Street to inspect the narrow basement ventilation window. This modest opening was the focal point of the final hours of the siege, where Nazi forces directed firehoses and tear gas into the crypt in an attempt to drown and flush out the paratroopers.

Surrounding the iron grille, deep bullet scars and shrapnel gouges remain deliberately preserved in the stone facade. Looking at this window from the outside gives an invaluable spatial perspective when you later stand directly beneath it inside the crypt, observing the marks where the defenders tried to dig an escape tunnel toward the city sewers.