Lost & Found is a monthly artist salon held in one of the medieval towers of the Waag on the Nieuwmarkt. In the room where Rembrandt's 'The Anatomy Lesson of Dr. Nicolaes Tulp' once took place have since 1997 over 80 sessions of stray images and sound been organized. Artists show material which doesn't fit comfortably into regular gallery contexts; work which demands more concentration than the usual walk-by. Check the Lost & Found website for dates & times.
The Bartolotti is perhaps one of the most beautiful Museum Houses Amsterdam has, built by someone who once was the richest man in the city, but it's a bit hidden in plain sight. These days, it is run by a group of lovely old ladies, who can't wait to offer you tea or juice. You can walk around the house like you live there.
You have to ring the doorbell to get in.
(picture from Google, by Arjan Bronkhorst)
I love how small this place is, but it offers such amazing quality in cheeses, meats, wines, bread etc. You can also have lunch here. Definitely worth picking up fresh food here!