City Council President Darlene Harris unveiled two display cases Tuesday morning outside council chambers in City Hall featuring historical documents and memorabilia.

Included are the official charters of the City of Pittsburgh and what was then the Borough of Pittsburgh; flags of Pittsburgh’s 16 sister cities; and gifts presented to the city from visiting dignitaries.

The cabinets were paid for with money allocated for the Sister City program. Pittsburgh’s sister cities include Sheffield, England; DaNang, Vietnam; and Karmiel and Misgav, Israel.

The Sister City program began in 1956 to further exchanges between the United States and other countries.