Many of the neighborhood's streets are narrow and some curve at odd angles. This is generally regarded as adding to both the historic character and charm of the neighborhood. In addition, as the meandering Greenwich Street used to be on the Hudson River shoreline, much of the neighborhood west of Greenwich Street is on landfill, but still follows the older street grid.[16] When Sixth and Seventh Avenues were built in the early 20th century, they were built diagonally to the existing street plan, and many older, smaller streets had to be demolished.