Chamkar Mon is the southernmost district in central Phnom Penh, Cambodia. The district has an area of 10.56 km. As of the 2019 cens…Chamkar Mon is the southernmost district in central Phnom Penh, Cambodia. The district has an area of 10.56 km. As of the 2019 census, its population was 70,772. Chamkar Mon was subdivided into 12 Sangkats and 95 Phums.