Secret tunnel between biggest sovereign public gold vault and formerly biggest commercial gold vault?

Side by side on the map.

What's this?  The world's largest private gold vault is joined by a tunnel to the world's largest public sovereign gold vault and the former is emptying out and up for sale.  Zero Hedge reports JP Morgan is selling 1 Chase Manhattan Place which is just across the road from the Federal Reserve Bank of New York.  The two vaults are 90 feet underground, linked by a little known tunnel, and served by elevators that would lift a tank. The storage was developed on bedrock to survive an A bomb.

How solid are these facts?  The tunnel and elevator report comes from a one year old comment made on an earlier Zero Hedge article.  (Captain Kink: "I have seen it")   ie, not very solid.  On the other hand, that two extraordinary and same-purposed vaults are side by side is pretty good circumstantial support.  The Fed may not be the very biggest sovereign public gold vault on earth.

A related story: Germany has arranged to gradually get its national gold supply back from the NY Fed vault across the road but has not been allowed to verify the gold is there.
How big:  The Fed vault is built on bedrock to support 530,000 gold bars safely.This gold mostly belongs to foreign nations and is separate from the Fort Knox and West Point repositories of US gold.