Lord Elgin liberally interpreted this agreement to collect all the sculptures he could find, and he removed about half the remaining sculptures from the ruins of the Parthenon. Some he took roughly from the building, others he collected from the ground, and some he bought from local people. Lord Elgin sold these antiquities to the British Museum in 1816, where they are still on display in the Duveen Gallery. Over 200 years later, these pieces, called the "Elgin Marbles" remain a sore point between London and Athens. The Greek government demands the return of the Parthenon marbles, but the British government continues to hold and exhibit these significant pieces.
Good arguments regarding the "Elgin Marbles" or the "Parthenon Marbles" can be made for both sides, and the story is certainly fascinating!
To the left of the Parthenon, on the west side of the Acropolis, is the Erechtheum.

