Many diseases and conditions are spread by not washing hands with soap and clean, running water. If clean, running water is not accessible, as is common in many parts of the world, use soap and available water.
Riverdale covers about three square miles in area. It has one of the highest elevations in New York City, affording it views of the Empire State Building, George Washington Bridge, Hudson River and New Jersey Palisades.
Riverdale is on the waterfront, just south of Yonkers; it constitutes just about everything west of Van Cortlandt Park and north of the Harlem River. The No. 1 train is the only subway that goes there (actually, it ends there, at Van Cortlandt Park).