Cass Regional Medical Center anchors the 76,000-square-foot property in Harrisonville. : Montecito Medical Real Estate has purchased Rock Haven Medical Mall, a nearly 76,000-square-foot medical office building in Harrisonville, Mo. CEAH Realtors sold the Class A property nine years after completing its first phase of development, according to Yardi Matrix. Institutional Property Advisors and Colliers International arranged the transaction. Developed in phases in 2011 and 2014, the two-story building at 2820 E. Rock Haven Road is adjacent to Cass Regional Medical Center, a general acute-care hospital that also anchors Rock Haven Medical Mall.