The mostly unbroken line of elegant apartment buildings along Riverside Drive on the Upper West Side appear from afar like early 20th century residential fortresses.

But look closely past the black iron fence at one building on the corner of 92nd Street. You'll catch a glimpse of a sliver of colonial-era Manhattan that isn't on modern-day maps and doesn't adhere to the circa-1811 street grid.

The 7-story residence is 194 Riverside Drive (below), completed in 1902 and designed by Ralph Samuel Townsend, an architect who lived on 102nd Street and designed buildings all over the city—including the richly detailed Kenilworth on Central Park West.

"The wide alleyway on the south side of the building is the remnant of a path or lane that once led from the old Bloomingdale road (slightly off line with Broadway) to Twelfth Avenue," wrote the Landmarks Preservation Commission in their 1989 report designating this stretch of Riverside Drive a historical district.

The unnamed lane, which runs on the north side of 190 Riverside next door, "separated the farms of Brouckholst Livingston to the south and R.L. Schieffelin to the north."

These farms and others were part of the village of Bloomingdale (image above), a once rural swatch of today's Upper West Side that served as farmland, then the site of estates and institutions, and by the late 19th century was absorbed into the larger city.

An 1890s map of the neighborhood (below, click the link to zoom in) shows us exactly where this farm lane once ran.

Between 91st and 92nd Streets, you can see faintly outlined blue lines going from the river to the former Bloomingdale Road—which opened in 1703 and offered access to and from the rest of Manhattan to this beautiful part of Gotham. (Bloomingdale came from the Dutch Bloemendaal, which meant "valley of flowers.")

Today, the lane would extend from the courtyard on the south side of 194 Riverside Drive, through the backyards of row houses past West End and Avenue. Google maps allows us to trace the path, and then imagine the colonial-era farmers and estate owners who traversed it centuries ago.

[Second image: Wikipedia; third image: NYPL; fourth image: LOC]