The World's Oldest Subway Tunnel And Its Advocate. Bob Diamond, a local Brooklyn resident, for years talked about finding the "lost" former Brooklyn and Jamaica/Long Island Rail Road (current day MTA LIRR) "Cobble Hill" or "Atlantic Avenue" Tunnel (not the current alignment). The whole story would take up books, but the tunnel carried trains from 1845-1861, itself a realignment from street running, and is considered the World's Oldest Subway Tunnel. From then until Bob rediscovered it in 1980 and crawled through the 2 foot wide passage, is was mostly sealed up and closed. Bob spent untold hours excavating all of the dirt by hand, eventually running his own walking tours. One of those things that we thought would be around forever, I hadn't prioritized it but finally went down for the tour with Bob on December 6, 2009. We entered through a manhole in the middle of the street and as advertised it was old, dark, dirty and gigantic. About a year later, the city pulled the permit for him to run tours and it has not been restored since. Bob died in 2021, and the future of this tunnel is unknown.