Museum Night returns again this year, kicking off at 7pm on this Saturday, June 9.
50 different museums, galleries, and cultural institutions will be open for free between 7 pm and 1 am. There will be 10 special bus routes provided to ferry visitors between museums, with a central interchange at Namesti Jana Palacha. The buses will be free of charge.
You can find a full list of the museums here.
If you're in Prague this weekend, then I highly recommend that you partake in this event. It's tremendously good fun, and there is something kind of wonderful about wandering around a museum at night with a crowd of local people.