The Gate of Mazeus and Mithridates is a triumphal arch located at the end of Curetes Street in the Celsus Library Court. It was built in 40 A.D by the slaves Mazeus and Mythridates. They built this gate in honor of the emperor Augustus who gave them both their freedom and sent them to Ephesus to serve as officers in charge of maintaining the properties belonging to the Roman Empire.The side of the Gate of Mazeus and Mithridates that faces the Celsus Library is made entirely of black marble. The opposite side of the gate is made entirely of white marble.