Mount Prospect/Mount Pleasant
Park Avenue at East 93rd Street
Though many of its slopes were flattened when the street grid was imposed in the early 19th century, the Upper East Side’s natural topography is quite hilly. The slope at this section of Park Avenue was once prominent, and was referred to as “Mount Prospect” or “Mount Pleasant.” In 1837, a railroad tunnel was cut through the hill to bring day-trip visitors to upper Manhattan. A grand hotel, Prospect Hall, was built near what is now East 93rd Street. Situated on 12 acres, visitors could take in views of the city, as well as Long Island and New Jersey.
(Note- Picture shown is the Park Avenue tunnel. Picture from Forgotten NY )