From the Israel Antiquities Authority: A Silver Coin That Was Used To Pay The Half Shekel Head-Tax To The Temple Was Found In Jerusalem.

This coming Thursday, before reading the Scroll of Esther, all devout Jews will contribute a sum of money — "a reminder of the half shekel" — which is a tradition that took root in the wake of the ancient virtuous deed of paying a tax of one half shekel to the Temple. This sum, which was used in the past for the purpose of establishing and maintaining the temple, is translated into a contemporary amount and donated to the needy.

In an archaeological excavation that is being conducted in the main drainage channel of Jerusalem from the time of the Second Temple, in the City of David, in the Walls around Jerusalem National Park, an ancient rare silver coin was recently discovered. This coin is a shekel denomination that was customarily used to pay a half shekel head-tax in the Second Temple period. [continue, see photo]