The Elgin Marbles

I neglected to mention that all of this art is from the Parthenon, in the British Museum, in case you hadn't already figured it out. 

The Parthenon collection, also known as the Elgin Marbles after the ambassador to the Ottoman Empire who removed them from the Parthenon and transported them to Britain at the beginning of the nineteenth century, are of course the subject of a long-running dispute with Greece. (The builders of the Acropolis Museum in Athens clearly expect to get them back some day; they have replicas of everything that's in London and make it obvious that they consider the fakes a temporary solution.)

The British Museum offers a pamphlet in the exhibit, explaining the history of the marbles and also making it clear that they have no intention of giving them to anyone. 

The [British] Museum is a unique resource for the world: the breadth and depth of its collection allows the world's public to re-examine cultural identities and explore the connections between them. Within the context of this unparalleled collection, the Parthenon sculptures are an important representation of the culture of ancient Athens. Millions of visitors admire the beauty of the sculptures each year -- free of charge....The Acropolis Museum allows the Parthenon sculptures that are in Athens to be appreciated against the backdrop of ancient Greek and Athenian history. This display does not alter the Trustees' view that the sculptures are part of everyone's shared heritage and transcend cultural boundaries.