Mark Seiden Best Real Estate Agent 1238 Pleasantville Road Town of Ossining, New York, 10510 Phone: 914-762-2200 Website Company Name: Mark Seiden Real Estate Team Area of Expertise: Briarcliff Manor Profile Let this business know you found them on Westchester Magazine's Online Directories. Locations Town of Ossining 1238 Pleasantville Road Town of Ossining, New York 10510 Claim/Edit Listing