What it's like to go inside New York City's dank, dangerous, bug-filled sewers

Former explorer says the worst part of NYC sewers wasn’t rats or smell but cockroaches “crawling on walls, dropping down on you.”
Many 19th-century sewer mains are surprisingly large and architecturally striking — brick arches that follow old buried streams beneath the city.
Viral videos show groups spending up to three hours underground; explorers say trips are usually well-timed and gear-heavy, driven by curiosity rather than treasure.