A detail from an exquisite map of Central Park, published in 1865. The map appeared in A picturesque Guide through the whole Park showing all the improvements up to June 1865, published by L. Prang, Boston.
The reservoir was drained in 1931 and filled with excavation material from Rockefeller Center and the Eighth Avenue subway. Today it is the site of the Great Lawn.
The full map can be seen at the David Rumsey Map Collection.