Rodin's The Thinker

There are many castings in different sizes displayed all over the world. This one is a smaller version than the original one which Rodin originally designed as Le Poète (The Poet) as part of a commissioned work for an ornate doorway in Paris in 1880.
Find out more about the work on Wikipedia.

This one in black I saw today in the newest museum in Brussels, the Fin de Siecle Museum within the complex of the Royal Belgian Museums for the Fine Arts.

I once captured a monkey in a very similar pose by the way !