Riverdale is a residential neighborhood in the northwest portion of the Bronx. When it was first developed, many Manhattan moguls built their country estates there, for example, in what is now known as the Fieldston area (which is designated a national historic district). In the early 20th Century, with the ease of train commuting, many people made Riverdale their full-time residence. Riverdale is made up of a number of subsections: Central Riverdale (downtown area), Fieldston, Hudson Hill, North Riverdale, Mosholu, Spuyten Duyvil and Villanova Heights. Riverdale housing is made up of new construction rentals and condos to post-war co-ops to gorgeous mansions. Riverdale is home to a number of elite private schools, including Horrace Mann, Fieldston and Riverdale Country School.