From the outside, the Morgan Library and Museum doesn't look like a space that would house three Gutenberg Bibles, letters from George Washington and Abraham Lincoln, and a manuscript from Mozart.
The museum complex, which spans half a city block in midtown Manhattan, was originally a series of private residences owned by John Piermont "JP" Morgan, the legendary financier credited with rescuing America from a financial crisis in the 1900s.
Morgan founded the banking firm now called JPMorgan Chase & Co. in 1871. Today, it's the largest bank in the US.
The complex 's multiple structures have since been sewn together and opened to visitors. A café and gift shop are located inside a brownstone that once belonged to Morgan's son, and Morgan's own private rooms - a study, librarian's office, and main library - are found in the museum's central building. An annex where Morgan's personal residence once stood now holds galleries.
Morgan dedicated the last two decades of his life to searching for rare, expensive finds to add to his vast art collection. He spent $900 million (in today's dollars) on art and rare artifacts, some of which are still housed in his private rooms.
Business Insider toured these rooms as part of Open House New York, a weekend-long event that grants entry to closed-off sites throughout the city. Among the more fascinating elements of the complex were a hidden staircase, fake bookcases, and a secret vault. Take a look.