I only came across Europeana recently. It is a website where galleries, museums and libraries from across Europe are providing access to their collections. The British Library, The Louvre and the Rijksmuseum are just three of the many institutions contributing to this site.
From the about page:
Explore millions of items from a range of Europe’s leading galleries, libraries, archives and museums. Books and manuscripts, photos and paintings, television and film, sculpture and crafts, diaries and maps, sheet music and recordings, they’re all here. No need to travel the continent, either physically or virtually!
Found something you like? Download it, print it, use it, save it, share it, play with it, love it!
Search results include images, text, video and sound recordings. It is easy to refine a search with the options on the left hand side. I particularly like how you can limit your search to display items that are licensed for re-use if you wish. This search result shows 160 image, text and videos related to medical instruments that can be re-used with attribution or with restrictions.
The contributing institutions are from all over Europe so the built-in translation service is handy.
You can register for a Europeana account if you wish which allows you to save items for future reference.