Arpa Darreh (, also Romanized as ÃÂrpÃÂ Darreh and ÃÂrpÃÂdarah; also known as ÃÂrpeh Darreh) is a village in Sardrud-e Olya Rural District, Sardrud District, Razan County, Hamadan Province, Iran. At the 2006 census, its population was 955, in 229 families.