Two short sections of Ninth Avenue also exist in the Inwood neighborhood, carrying two-way traffic.

The buildings are separated in mid-block by the narrowest of access alleys, giving glimpses of Ailanthus foliage in the side-street yards.

The repeated designs of three or four commercial speculative builders, using the same features and detailing, add to the avenue's architectural unity.

There are several generously scaled pre-World War I apartment buildings and the former Endicott Hotel, as well as a small commercial block from the office of McKim, Mead, and White at 72nd Street.

Between 77th and 81st Streets, Columbus Avenue borders the American Museum of Natural History and Theodore Roosevelt Park.

[1] The addresses along this upper stretch from 201st Street to Broadway are continuous with the lower portion of Ninth Avenue.