Met Kids - Hop in the time machine or follow the map.
This site has activities for different artworks and a variety of videos.
Tate Kids- Enjoy illustrations like this one by Marcus Walters.
More for younger kids, but it has great activities, information about artists and styles.
Google Arts & Culture is an online platform with has high-resolution images and videos of artworks and cultural artifacts from partner cultural organizations throughout the world. You are able to take tours through a variety of collections and galleries and it provides information on the works.
Anne Frank Video Diary - Hosted by the Anne Frank Museum
The Anne Frank video diary will air on YouTube in fifteen episodes. Luna Cruz Perez plays Anne Frank, sharing her life in the Secret Annex, her thoughts and her feelings with the camera. All characters, locations, and events in the series are based on Anne Frank's diary letters.