Outside the main hall there is a glass-floored ramp, through that glass one can see some minor mosaics. This is one of them.

From the Wikipedia: "After Zeus impregnated Antiope, Antiope fled in shame to King Epopeus of Sicyon, but was brought back by Lycus through force, giving birth to the twins Amphion and Zethus on the way. Lycus gave Antiope to Dirce. Dirce hated Antiope and treated her cruelly, until Antiope, in time, escaped.[1][2]

In Euripides' lost play Antiope, Antiope flees back to the cave where she gave birth to Amphion and Zethus; they are now living there as young men. They disbelieve her claim to be their mother and refuse her pleas for sanctuary, but when Dirce comes to find Antiope and orders her to be killed, the twins are convinced by the shepherd who raised them that Antiope is their mother. They kill Dirce by tying her to the horns of a bull. "

The mosaic was found in 1964 during works on a building for a bank. It dates from late third, early fourth century.