COBBLE HILL - A local train enthusiast is trying to reopen an old historic train tunnel that was closed four years ago.

Bob Diamond, president of the Brooklyn Historic Railway Association, was conducting tours in the tunnel under Atlantic Avenue for decades. In 2010, the FDNY shut down his operation after they deemed the tunnel to be unsafe for the public.

Diamond disagrees and has drafted a study to bring it back. In his proposal, he talks about preserving the tunnel by restoring it as a museum and improving public access. He says the restoration would cost about $3 million.

"It's a historical artifact. The world's oldest subway. But more than that, we've had tours down here for over 20 years and it draws a lot of people from all over the country, all over the region, all over the world," Diamond said.

The FDNY refused to comment on the issue as it is an active case.