Open Data Portal

https://data.cityofnewyork.us/Housing-Development/Individual-Landmarks/ch5p-r223

This dataset is regularly updated and includes descriptive info. Includes both designated and "calendared" (under consideration) individual landmarks.

The subset of points with lm_type = ‘Individual Landmark’ are commonly referred to as 'individual landmarks.'

ArcGIS REST Services

As of winter 2020 the Landmarks Preservation Commission publishes ArcGIS REST data services supporting the Discover New York City Landmarks application, including Individual Landmarks at this ArcGIS online rest service. It may be password-protected.

https://services5.arcgis.com/Oos4pNA2538iVFA1/ArcGIS/rest/services