If you expand the list of services from Google's support page, you'll find an interesting service: Open Gallery. Clicking the link redirects you to the main Google support site.
I tried to find this service and searched for [open gallery]. Most of the results are about art galleries. Google actually has a service that brings museums online: Google Cultural Institute's Art Project. "Museums large and small, classic and modern, world-renowned and community-based from over 40 countries have contributed more than 40,000 high-resolution images of works ranging from oil on canvas to sculpture and furniture. Some paintings are available in 'gigapixel' format, allowing you to zoom in at brushstroke level to examine incredible detail," explains Google.
I've checked the source code of some Art Project pages and found this: "New! Artists, museums, galleries, archives: discover Google Open Gallery, powerful free tools to bring your content online." Google Open Gallery pointed to google.com/opengallery, which shows a 404 error message.
{ Merci, TomHTML. }