Warsaw's participation in the European Night of Museums started in 2004 with just 11 locations participating. Over twenty years later, the city boasts over 300 participating cultural institutions, including some that are typically inaccessible to the general public. As is the case across all of Poland's major cities, and much of Europe, the Night of Museums is a special evening in which Warsaw's museums, galleries and other cultural institutions stay open all evening (and even past midnight), organising special events, most of which are completely free. Also, you can expect to see vintage trams and buses providing free transportation to the many sites taking part. Check the website to see all of the many events taking place and plan your evening.