A park facing the new towers set to rise at the Ground Zero site could wind up being more topographically interesting than planned if a new proposal for the towers’ parking garages goes ahead as scheduled. “The ramps, which will lead to underground parking and loading docks for the giant complex, will have to accommodate the headroom needed for buses and trucks. And because the land drops as it approaches the Hudson River, the west end of the park may end up as a berm 25 to 30 feet above street level.”