The Bronx

===Location and physical features===

{{See also|List of smaller islands in New York City}}

According to the [[U.S. Census Bureau]], Bronx County has a total area of {{convert|57|sqmi}}, of which {{convert|42|sqmi}} is land and {{convert|15|sqmi}} (27%) is water.<ref name="GR1">{{cite web |url=https://www.census.gov/geo/maps-data/data/docs/gazetteer/counties_list_36.txt |archive-url=https://web.archive.org/web/20140519062322/http://www.census.gov/geo/maps-data/data/docs/gazetteer/counties_list_36.txt |url-status=dead |archive-date=May 19, 2014 |publisher=United States Census Bureau |access-date=January 3, 2015 |date=August 22, 2012 |title=2010 Census Gazetteer Files}}</ref>

{{anchor|Fordham gneiss}}The Bronx is New York City's northernmost borough, New York State's southernmost mainland county and the only part of New York City that is almost entirely on the North American mainland, unlike the other four boroughs that are either islands or located on islands.<ref name="GR6">{{cite web|url=http://www.naco.org/Counties/Pages/FindACounty.aspx |access-date=June 7, 2011 |title=Find a County |publisher=National Association of Counties |url-status=dead |archive-url=https://web.archive.org/web/20110531210815/http://www.naco.org/Counties/Pages/FindACounty.aspx |archive-date=May 31, 2011 }}</ref> The [[bedrock]] of the [[West Bronx]] is primarily ''Fordham [[gneiss]]'', a high-grade heavily banded [[metamorphic rock]] containing significant amounts of [[feldspar|pink feldspar]].<ref>The fact that the immediate layer of bedrock in the Bronx is Fordham gneiss, while that of Manhattan is schist has led to the expression: "The Bronx is gneiss (nice) but Manhattan is schist." {{cite concrete|page=42, n1}}</ref> Marble Hill – politically part of Manhattan but now physically attached to the Bronx – is so-called because of the formation of [[Inwood marble]] there as well as in [[Inwood, Manhattan]], and parts of the Bronx and Westchester County.

The [[Hudson River]] separates the Bronx on the west from [[Alpine, New Jersey|Alpine]], [[Tenafly, New Jersey|Tenafly]] and [[Englewood Cliffs, New Jersey|Englewood Cliffs]] in [[Bergen County, New Jersey]]; the [[Harlem River]] separates it from the island of [[Manhattan]] to the southwest; the [[East River]] separates it from [[Queens]] to the southeast; and to the east, [[Long Island Sound]] separates it from [[Nassau County, New York|Nassau County]] in western Long Island. Directly north of the Bronx are (from west to east) the adjoining [[Westchester County, New York|Westchester County]] communities of [[Yonkers, New York|Yonkers]], [[Mount Vernon, New York|Mount Vernon]], [[Pelham Manor, New York|Pelham Manor]] and [[New Rochelle, New York|New Rochelle]]. There is also a short southern land boundary with [[Marble Hill, Manhattan|Marble Hill]] in the Borough of Manhattan, over the filled-in former course of the [[Spuyten Duyvil Creek]]; Marble Hill's postal [[ZIP code]], telephonic [[area codes]] and fire service, however, are shared with the Bronx and not Manhattan.<ref name=NYT1993/>[[File:New York aerial night 2018e.jpg|thumb|Aerial view of the Bronx from the east at night|left]]

The [[Bronx River]] flows south from Westchester County through the borough, emptying into the East River; it is the only entirely [[freshwater]] river in New York City.<ref name="nytimes">{{cite news |first=Joseph |last=Berger |title=Reclaimed Jewel Whose Attraction Can Be Perilous |url=https://www.nytimes.com/2010/07/20/nyregion/20river.html?ref=nyregion |work=[[The New York Times]]|date=July 19, 2010 |access-date=July 21, 2010}}</ref> It separates the West Bronx from the schist of the [[East Bronx]]. A smaller river, the [[Hutchinson River]] (named after the religious leader [[Anne Hutchinson]], killed along its banks in 1641), passes through the East Bronx and empties into [[Eastchester Bay]].

The Bronx also includes several small islands in the [[East River]] and [[Long Island Sound]], such as [[City Island, New York|City Island]] and [[Hart Island (New York)|Hart Island]]. [[Rikers Island]] in the East River, home to the large jail complex for the entire city, is also part of the Bronx.

The Bronx's highest elevation at {{convert|280|ft|m|0}} is in the northwest corner, west of [[Van Cortlandt Park]] and in the Chapel Farm area near the [[Riverdale Country School]].<ref>[http://www.peakbagger.com/peak.aspx?pid=7110 Bronx High Point] and [http://www.peakbagger.com/climber/ascent.aspx?aid=33535 Ascent of Bronx Point on June 24, 2008] at Peakbaggers.com, retrieved on July 22, 2008</ref> The opposite (southeastern) side of the Bronx has four large low peninsulas or "necks" of low-lying land that jut into the waters of the East River and were once [[salt marsh]]: Hunt's Point, Clason's Point, Screvin's Neck and [[Throggs Neck]]. Further up the coastline, [[Rodman's Neck]] lies between [[Pelham Bay Park]] in the northeast and [[City Island, New York|City Island]]. The Bronx's irregular shoreline extends for {{convert|75|sqmi|km2|0}}.<ref>[http://bronxboropres.nyc.gov/en/gv/president/waterfront.htm Waterfront Development Initiative] {{webarchive|url=https://web.archive.org/web/20080919220603/http://bronxboropres.nyc.gov/en/gv/president/waterfront.htm |date=September 19, 2008 }}, Bronx Borough President's office, March 19, 2004, retrieved on July 29, 2008</ref>