President Barack Obama started his final day in Greece with a tour of the Acropolis, the nation's most famous ancient monument.
A picture posted by the US Embassy on Twitter showed Obama during a private tour on the ancient citadel by Dr Eleni Banou of the Greek Ministry of Culture.
The ancient site will remain closed to the public for the day to accommodate the president's visit.
Obama will also deliver a speech to the Greek people as he winds up the first leg of his final foreign tour as president and heads from Greece to Germany.
The president is expected to touch on both the country's efforts to emerge from its financial crisis, and on its role in dealing with hundreds of thousands of refugees who have crossed Greece's borders on their way to more prosperous European countries.
Obama's visit to Greece is the first official visit by a sitting US president since Bill Clinton. [Combined reports]