But anchoring them to Dubai's soft and unstable terrain poses one of the project's biggest engineering hurdles. "We typically build arches at locations where you have very good, solid rock, because the full weight of the arch is pushing against the ground," says Parsons engineer Ken Serzan. "But there is no rock here, just sand and then sandstone." So instead of installing the standard arch abutment, engineers will drill 200 holes -- six and a half feet wide and 130 feet deep, half vertical and half inclined -- and fill them with steel- reinforced concrete. Spaced about 20 feet apart and topped off with a concrete cap, the enormous foundations can absorb and dissipate the full force of the bridge. Once the Sixth Crossing is completed in 2012, it will be more than simply a traffic fix. It will be a destination in its own right.