Fortunately for Pompey, Hyrcanus II still had supporters in the city. They opened a gate, probably situated in the northwestern part of the city wall, and let the Romans in. This allowed Pompey to take hold of Jerusalem's upper city, including the Royal Palace, while Aristobulus' party held the eastern portions of the city—the Temple Mount and the City of David. The Jews consolidated their hold by breaking down the bridge over the Tyropoeon Valley connecting the upper city with the Temple Mount. Pompey offered them the chance to surrender, but when they refused, he began prosecuting the siege with vigour. Pompey had his forces construct a wall of circumvallation around the areas held by the Jews and then pitched his camp within the wall, to the north of the Temple. Here stood a saddle allowing access to Temple, and it was therefore guarded by the citadel known as the Baris, augmented by a ditch. A second camp was erected south-east of the Temple.