Clearly a hoax website, but nicely done:
The Manhattan Project of 1853: The 500-acre, secret subterranean city that lies 100 feet beneath Central Park in Manhattan.
The US government’s super secret hiding place for Czar Nicholas, Adolf Hitler, the Roswell aliens, and now… Howard Stern.
http://centralpark-ny.us/

All the czar rumors were correct!!!  except for the fact that the DNA matched relatives when the bodies were found.  Antibiotics were discovered in the 1920’s starting with pinicillin

Didn’t I see a movie about that once??