Slavery began in Rio in the mid-1770s. In 1811, Valongo Wharf was built along the waterfront to accommodate their importation and trade. More than a half million people from Angola plus East and Central West Africa passed through Cais do Valongo until 1831 when trafficking was banned. In 1843, this was renamed Empress Wharf. In 1911, the old slave market was buried. One hundred years later, the wharf was discovered when the port was being refurbished. Among the archeological findings were artifacts from this dark period of history. Valongo Wharf was designated a World Heritage Site in 2017.