Like Delphi, as a temple complex Olympia was a repository of dedicated gifts, some of which have survive to the present day.
Shields and spears:
A bronze cuirass:
This pair of helmets was one of the high points of the trip for me. They were dedicated sometime after 490 B.C. after the Battle of Marathon. To the left is a Persian helmet, to the right a Greek helmet.
Just visible is the name "Militiades", the Greek General (Archon) that lead the Greeks to victory. This was his helmet.
These are the remains of the Winged Nike (Nike of Paionios), one of the great statues of Olympia in her glory. The statue itself is 6' tall; it stood on an 18' pedestal which still exists. It was dedicated to commemorate victory over the Spartans at the Battle of Sphacteria in 425 B.C.
Carvings and statues:
This is a Roman statute - Hadrian, I believe:
A model of Olympia.