BROOKLYN - Decades after he discovered an abandoned Long Island Rail Road tunnel under Atlantic Avenue, a self-described historian is taking people underground to reach back into Brooklyn history.

Bob Diamond re-discovered the Atlantic Avenue subway tunnel in the 1980s. The tunnel was built in 1844 and was used for passengers for about 14 years, according to the Brooklyn Historical Railway Association.

Diamond leads visitors down a ladder, four stories underground to a cold, damp tunnel 17 feet high and 21 feet wide. He says he?s surprised at how successful the tours have been.

The Brooklyn Historical Railway Association was formed in 1982 to restore historic tunnels. It plans to conduct at least one tour of the Atlantic Avenue subway tunnel a month.

Diamond says the fees from the tours will go toward a project to bring trolleys back to Brooklyn.