Urban explorer Darmon Richter was able to get inside the nuclear bunker and offered us these pictures from his site The Bohemian Blog.
Richter titled the following slides himself to take BI Military & Defense readers on a personal tour of what he saw.
In Richter's own words:
My guide Svilen Slavov is a keen photographer and filmmaker. He had already paid numerous visits to the site, and had explored extensively in the bunker beneath.
On previous visits I had followed the flight of austere stone steps that form the main approach up to the imposing monument above; instead Svilen led me around the side of the hill, following a footpath that skirted a circumference beneath the dappled shade of thick green canopies. Pausing at a clearing in the bushes roughly a quarter of the way around, he gestured towards the mound itself - and there, set deep into the vegetation that bordered our path, I spied the rocky opening.
The main doorway to the nuclear bunker, located deep beneath the monument, was welded shut and impossible to pass. However, we found a secondary entrance hidden in bushes halfway up the hill.
The text painted onto the iron door reads: "СТРОГО ЗАБРАНЕНО": Bulgarian for "ENTRY STRICTLY PROHIBITED". We took it more as a recommendation, than an instruction.
Making our way into the tunnels, we passed through a series of cylindrical passages separated by concrete bulkheads.
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