 A "khachkar" (Armenian cross-stone), high and made of volcanic rock, stands at the entrance of the Church of the Archangel Gabriel in the Belgrade municipality of Zemun.The monument was erected in 1993, and it commemorates the Serbian pilots who perished in a plane crash in 1988 while transporting humanitarian aid to Armenia after the country was struck by a catastrophic earthquake.A colony of Armenian immigrants in Serbia existed in the 17th century.