City. New York City brownstones can cost several million dollars to purchase. A typical architectural detail of brownstones in and around New York City is the stoop, a steep staircase rising from the street to the entrance on what amounts to almost the second-floor level. This design was seen as hygienic at the time many were built, because the streets were so foul with animal waste. It has become fashionable to use the term "brownstone" to refer to almost any townhouse from a certain period, even though they may not have been built of brownstone. For example, many townhouses in Boerum Hill, Brooklyn, are built of brick, but have concrete masonry cladding which resembles stone. There are also many brick townhouses that have brownstone-built stoops throughout the outer boroughs. Such neighborhoods that consist of these homes are Borough Park, Dyker Heights, Bensonhurst, Bath Beach, Sunset Park, Kensington, Flatbush, Midwood, East New York, Cypress Hills in Brooklyn, Ridgewood, Glendale, Astoria, Woodhaven in Queens, and Longwood and Morrisania in the Bronx. The Rittenhouse Square and Fairmount neighborhoods of Philadelphia also include examples of brownstone architecture. Many of these homes have been converted into apartment buildings. Back Bay, Boston, is known for its Victorian brownstone homes – considered some of the best-preserved examples of 19th-century urban design in the United States. Although some brownstones exist in Chicago, a similar residential form known as "greystones" is far more prevalent. A greystone is a type of residential structure that utilizes Indiana limestone for its facade, regardless of its overall architectural style. As in Brooklyn, there is a "Greystone Belt" in Chicago, with large numbers of such structures located in the south and northwest quadrants of the city. It is estimated that around 30,000 of Chicago's greystones built between 1890 and 1930 are still standing. Use in colonial country homes Brownstone, also known as freestone because it can be cut freely in any direction, was used by early Pennsylvanian Quakers to construct stone mills and mill houses. In central Pennsylvania, some 1700s-era structures survive, including a residence known as the Quaker Mill House. Use in tombstone making Brownstone was prized by tombstone carvers in southern New England, and Mid Atlantic region during the Colonial era. Table-type memorials in particular were often carved out of brownstone as well as regular headstones. Especially valued for being easy to carve, those same characteristics often resulted in stones being less