It is the most important archaeological museum in Greece and one of the richest in the world concerning ancient Greek art. Its collections are representative of all the cultures that flourished in Greece.
These statuettes are from Cyclades civilizations. In the museum you can also see prehistoric items, sculpture, pottery and minor art, bronzes and Egyptian Art.
It's very close to Omonoia Square, accessible from the red or green metro line.
The Museum in Google Maps
P.S. Many thanks to my friend Jois who took the photos.