The Elgin Marbles are a collection of classical Greek marble sculptures that originally decorated the Parthenon and other buildings on the Acropolis of Athens. They were removed by Lord Elgin, a British ambassador to the Ottoman Empire, in the early 19th century and later acquired by the British Museum in London. The controversy lies in Greece's ongoing request for the return of the marbles to their place of origin, sparking debates about cultural heritage and ownership.