From the WHC Inscription:
In the 1990s conflict, however, most of the historic town and the Old Bridge, designed by the renowned architect Sinan, was destroyed. The Old Bridge was recently rebuilt and many of the edifices in the Old Town have been restored or rebuilt with the contribution of an international scientific committee established by UNESCO.
The Old Bridge area, with its pre-Ottoman, eastern Ottoman, Mediterranean and western European architectural features, is an outstanding example of a multicultural urban settlement. The reconstructed Old Bridge and Old City of Mostar is a symbol of reconciliation, international co-operation and of the coexistence of diverse cultural, ethnic and religious communities.
Read more at http://whc.unesco.org/en/list/946