Editing Cobble Hill Tunnel (section)

== Rediscovery ==
Having fallen from public notice, the tunnel was rediscovered in 1980 by then 20-year-old [[Bob Diamond (engineer)|Bob Diamond]],<ref>{{cite news |url=https://www.nytimes.com/2021/08/28/nyregion/bob-diamond-dead.html |title=Bob Diamond, the ‘Tunnel King’ of Brooklyn, Dies at 61 |first=Clay |last=Risen |newspaper=[[The New York Times]] |via=nytimes.com |date=August 28, 2021 |accessdate=February 24, 2024}}</ref><ref>{{cite web |url=https://untappedcities.com/2014/02/11/abandoned-atlantic-avenue-tunnel-cobble-hill-brooklyn/ |title=Abandoned Atlantic Avenue Tunnel in Cobble Hill, Brooklyn: The World’s Oldest Subway Tunnel |first=Phillipe Martin |last=Chatelain |website=untappedcities.com |date=February 11, 2014}}</ref> who entered from a manhole he located at Atlantic Avenue and Court Street,<ref>{{cite news |url=https://www.newspapers.com/article/newsday-brooklyns-forgotten-tunnel/142039409/ |title=Brooklyn's Forgotten Tunnel |first=George |last=DeWan |newspaper=[[Newsday]] |date=September 17, 1980 |accessdate=February 24, 2024 |via=newspapers.com}}</ref> crawled a distance of {{convert|70|ft|m}} underground through a filled-in section of tunnel less than {{convert|2|ft|m|spell=in}} high, and located the bulkhead wall that sealed off the main portion of the tunnel. With the assistance of a [[Brooklyn Union Gas Company]] engineering crew, he then broke through the massive concrete bulkhead wall, which is several feet thick. Diamond thereby opened access to the main portion of the tunnel, and began to popularize the tunnel as an antiquity. He led tours of its interior<ref name=CB /> for his [[Brooklyn Historic Railway Association]], from 1982 until December 17, 2010,<ref>{{Cite web|url=http://www.nbcnewyork.com/news/local/Brooklyn-Underground-Tunnel-Tours-Are-Now-Six-Feet-Under-112103379.html|title=Brooklyn Underground Tunnel Tours Are Now Six Feet Under|website=NBC New York}}</ref> when the [[New York State Department of Transportation|Department of Transportation]] terminated his contract, citing safety concerns.<ref name=theverge>[https://www.theverge.com/2014/2/5/5280920/tunnel-vision-bob-diamond-fights-for-the-atlantic-avenue-subway Tunnel vision: how an obsessed explorer found and lost the world's oldest subway] - ''The Verge'', 2014</ref> The tunnel has been listed on the [[National Register of Historic Places]] since 1989.<ref name="nris"/>

The [[History (U.S. TV channel)|History Channel]] series ''[[Cities of the Underworld]]'' ran a segment ("New York's Secret Societies") on the tunnel in 2008.<ref>{{Citation|title=New York's Underground Societies {{!}} Cities of the Underworld (S2, E9) {{!}} Full Episode {{!}} History|url=https://www.youtube.com/watch?v=Uc344Z7peS8|language=en|access-date=2021-09-03}}</ref>