Although they are not particular to Manhattan, stoops are a particularly useful architectural feature on the grid. The 1811 plan did not include alleyways within the city blocks or spaces between the property lots, and as a result it can be difficult—or impossible—to enter a building on the grid from any direction except the front. A stoop eliminates the need for a back door by making it possible to enter a partially sub-grade basement via a short flight of steps down from the sidewalk. Another short flight up allows the building’s first residential floor to be a half-story above the street, removed from noise and activity. CY and CS