SustanSustan is a village in Layl Rural District of the Central District in Lahijan County, Gilan province, Iran.DemographicsPopulationAt the time of the 2006 National Census, the village's population was 4,341 in 1,229 households. The following census in 2011 counted 2,069 people in 647 households. The 2016 census measured the population of the village as 2,336 people in 777 households. It was the most populous village in its rural district.