Archaeologists have unearthed a pyramid-shaped staircase in the City of David. They believe it dates back to the Second Temple period, but can only guess at its function:
This structure [is] situated alongside the 2,000-year-old Second Temple-era stepped street, which carried pilgrims on their way from the Shiloah (Siloam) Pool to the Temple, which stood atop the Temple Mount. . . .
According to archaeologists Nahshon Szanton and Joe Uziel, . . . “the structure exposed is unique. To date, such a structure has yet to be found in the numerous excavations that have taken place in Jerusalem and, to the best of our knowledge, outside of it. For this reason, its exact use remains enigmatic. The structure is built along the street in a place that is clearly visible from afar to passers-by making their way to the Temple. We believe the structure was a kind of monumental podium that attracted the public’s attention. . . .
“It would be very interesting to know what was said there 2,000 years ago. Were messages announced here on behalf of the government? Perhaps news or gossip, or admonitions and street preaching?”
Read more on Israel Antiquities Authority: http://www.antiquities.org.il/Article_eng.aspx?sec_id=25&subj_id=240&id=4144