'Collection of collections' of the University of Amsterdam. Bijzondere Collecties has archives, old books, portraits, scientific artefacts, medieval handwritings, old maps and much more, all collected since 1578.
Regularly has really interesting exhibitions from their own collection.

Address:
Oude Turfmarkt 129, Amsterdam
Web:
http://www.bijzonderecollecties.uva.nl/en/

Opening hours:
Tu-Fr 10-5
Sa-Su 1-5
The exhibition is closed on 1 January, King's Day (27 April), and Christmas Day (25 December).
The exhibition is open, however, on Easter Sunday and Easter Monday, Ascension Day, Whitsun and Whit Monday, and Boxing Day.