The recent discovery of what are thought to be some of the missing megaliths from Stone Henge has been covered extensively in the Greek media during the last week. The stones were found at a site (the location of which is being kept secret whilst a full archaeological study is being carried out) in the Peloponnese. It is thought that they were taken from Britain during Roman times, whilst Greece was also part of the Roman Empire.
What has caused particular controversy in the UK, is the Greeks current refusal to consider returning these stones which are believed to have been an integral part of Britain’s most important historic monument.
Parliamentary Information Management Web Site
The Return of the Stonehenge Megaliths from Greece
That this House is euphoric about the news of the discovery of many of the missing megaliths from Stonehenge in a remote and mountainous area of the Peloponnese Peninsula in Greece to where they were taken to build an amphitheatre; considers this to be the single most important discovery in British archaeology for more than a century; yet is astounded at the brazen effrontery of the Greek authorities who have scandalously refused their return to Britain where they rightly belong; believes the Greeks have attempted to defend their decision with the kind of shameless and preposterous poppycock of an ancient colonial power; calls on the Greeks to put right the wrongs of their forefathers during that shameful period of ancient Greek imperial history; and asks HM Government on the day of the announcement of this find, April 1st 2009, to answer the extraordinary Greek claim that there is no difference between this and the holding by the British Museum of the Parthenon Marbles.
This follow-up article  has more details.