Archaeologists digging in Jerusalem have uncovered a 3,700-year-old wall that is the oldest example of massive fortifications ever found in the city, the Israel Antiquities Authority said Wednesday. The 26-foot-high wall is believed to have been part of a protected passage built by ancient Canaanites from a hilltop fortress to a nearby spring that was the city's only water source and vulnerable to marauders. The discovery marks the first time archaeologists have found such massive construction from before the time of Herod, the ruler behind numerous monumental projects in the city 2,000 years ago, and shows that Jerusalem of the Middle Bronze Age had a powerful population capable of complex building projects, said Ronny Reich, director of the excavation and an archaeology professor at the University of Haifa. The wall dates to the 17th century BC, when Jerusalem was a small, fortified enclave controlled by the Canaanites, one of the peoples the Bible says lived in the Holy Land before the Hebrew conquest. The kingdom thought to have been ruled from Jerusalem by the biblical King David is usually dated to at least seven centuries later. A small section of the wall was first discovered in 1909, but diggers have now exposed a 79-foot portion, and Reich believes it stretches much further. Reich said budget constraints related to the global financial crisis put an end to the excavation, at least for now. "The wall is enormous, and that it survived 3,700 years - this is, even for us, a long time," Reich said. It was remarkable that a fortification of this kind was not dismantled for later building projects, he said. "When you just stand there and see it, it is amazing," he said. The wall and other archaeological finds at the site will be opened to the public beginning Thursday, the Antiquities Authority said. Archaeological research at the site known as the City of David, just outside the walls of Jerusalem's Old City, is caught up in the struggle for control over the city. The archaeological site, one of the richest in a country full of ancient remains, is in the midst of a Palestinian neighborhood in east Jerusalem. The City of David digs are funded by Elad, a settler organization that also buys Palestinian homes and brings Jewish families into the neighborhood. Palestinian and Israeli critics have charged that the archaeology is being used as a political tool to cement Jewish control over parts of Jerusalem that Palestinians want for the capital of a future state.