The Harry Elkins Widener Memorial Library, housing some 3.5 million books in its "vast and cavernous" stacks, is the centerpiece of the Harvard College Libraries and, more broadly, of the entire Harvard Library system.
It honors 1907 Harvard College graduate and book collector Harry Elkins Widener, and was built by his mother Eleanor Elkins Widener after his death in the sinking of the RMS Titanic in 1912.
The library's holdings, which include works in more than one hundred languages, comprise "one of the world's most comprehensive research collections in the humanities and social sciences."
Wikipedia https://en.wikipedia.org/wiki/Widener_Library
Address (Unnamed Road), Cambridge 02138, United States
Coordinates 42°22'24.467" N -71°6'59.426" E