The Netherlands Architecture Institute (NAi) is a Dutch architecture institute in Rotterdam. The NAi owns one of the world’s largest architectural collections, has a library with over 30,000 books and a museum with 3 exhibition galleries. The NAi museum in Rotterdam (1993) is located in a modern building designed by architect Jo Coenen, located on the Museumpark in Rotterdam.
The second venue of the NAi in Maastricht is since April 2009 a separate museum by the name of NAiM / Bureau Europa and focuses on pan-European issues. Affiliate organization NAi Publishers publishes books about architecture, urban design, spatial planning, visual art, photography and design.
The year 2007–08 was proclaimed "Cuypersjaar" (Cuypersyear) in the Netherlands. During this year the NAi in Rotterdam and Maastricht presented the exhibition "Cuypers — architecture with a mission" about the famous architect Pierre Cuypers (Rijksmuseum and Central Station of Amsterdam)
From May 2010 until the spring of 2011 the NAi museum galleries are closed for a renovation. The library, archives and museum house remain open for the public.