sentences:  On September 19, 2011, Mayor Rahm Emanuel held a press conference in the newly opened expansion of the park to announce a plan to build a series of boat houses along the Chicago River.At about this time, the phase two five-acre riverfront expansion located to the north of the existing park expanded the park to the north of the 18th street bridge.It was also designed by Site Design Group, and features a 300 linear foot boardwalk with iconic red Chinese ornamental railings that extends over the water, as well as unique decorative limestone rocks called scholar's stones or Gongshi from Lake Tai in China.