I neglected to put up a link yesterday, so today you get two.
First up, Merriam-Webster’s Visual Dictionary On-Line. Arranged thematically, this is the interactive version of the familiar reference book. Great for when you can see something in your mind but can’t come up with the word for it, and just plain fun to explore
Second, because it’s so amazing, this high-def look at Leonardo DaVinci’s The Last Supper — a 16 BILLION bit image of the famous painting. You can zoom in to microscopic detail, back off to get the full effect, and generally be amazed by both how wondrous it is and how sadly deteriorated the plaster is. The tabs at the top of the page will lead you to more information on Leonardo and his work.
Go, visit, blow your mind.