On my opinion, the archeological museum of Amfipolis is one of the best, if you have the time (and the interest) to read the complete info presented. It offers a great way of presenting the history and the civilisation through the ages, although most of the findings, valuable for the archaeologists, are not so impressive by themselves. In the exhibition halls you can follow the cultural history of Amfipolis and the region since 6,000 BC and up to Post-Byzantine era, when it was abandoned and ruined.
Deriving its wealth both from the gold mines and the forests of the Pangaion mountain, the place, having strategic and economic importance, was colonised as Amfipolis by the Athenians in 437 BC, who fortified the city; its seaport was Eiona; during the Peloponnesian war it was conquered by the Spartans; in 357 BC was captured by Philippos II of Macedonia and became the main naval port for the expedition of Alexander the Great to the East.
The colossal animal, reassembled from fragments, has been mounted on a pedestal built on the ancient foundation with blocks of the 2nd century BC dredged from the Strymon river bed, where they may have been reused in a medieval dam.
In 1912-13, Greek soldiers found the base and some fragments of the statue. Later, during WW1, English soldiers discovered more pieces and more others were revealed in 1930-31, during works for the re-arrangement of Strymon riverbed.
French and American scientists and technicians guided the restoration of the Lion in 1936-37.
It is a work of the 5th or 4th century BC. Although, nothing is definitely proved about its construction and its ruining.