Websites such as Apartment Guide, Realtor and Craigslist give users ways to search through rental listings for apartments of all types, including basement and other below-ground property rental listings. The sites have various search and sorting utilities which allow users to filter results according to the story on which the apartment is located, isolating for basement units.
Realtor is a website that provides users with access to listings and with connections to affiliated realty agents in their areas. This can enable users to make more thorough, professionally-assisted assessments of given properties and rental agreements and to find properties that suit their preferences and budgets.
Apartment Guide allows users to search through apartment listings according to multiple criteria. These include rental pricing, location and the level of the building on which the apartment is located. This enables users to search specifically for basement apartments without having to enlist the services of a real-world listing agent or realtor to help them find what they are looking for.
Craigslist has apartment listings in almost every part of America grouped by state and by county. The listings are searchable, though not elaborately, and they are a good place to find basement units and other isolated spaces for rent.