Gentilly is bounded by Lake Pontchartrain, France Road, Bayou St. John and the Louisville and Nashville Railroad.

The major north-south streets are Franklin Avenue, Elysian Fields Avenue, St. Anthony, St. Bernard, St. Roch, Paris, Wisner, A.P. Tureaud (formerly London) Avenue and Press. The east-west streets are Lakeshore Drive, Leon C. Simon, Robert E. Lee (a section of which was formerly called Hibernia), Prentiss, Harrison, Filmore, Mirabeau, Hayne, Chef Menteur and Gentilly Boulevard.

The first part of Gentilly to be developed was along the Gentilly Ridge, a long stretch of high ground along the former banks of BayouGentilly. A road, originally named Gentilly Road was built on the ridge, and formed a path into today’s French Quarter. The high ground became Gentilly Boulevard and U.S. Highway 90, part of the Old Spanish Trail which stretches from St. Augustine, Florida to Los Angeles, California.

Settlement was originally confined to this long narrow ridge, since most of the ground between the ridge and the lake was swampy. The first residential section adjacent to the ridge, Gentilly Terrace, dating to the early 20th century, was built by excavating and piling up the earth in the shallow swamp to create blocks of terraced land where houses could be built. With the development of improved drainage pumps, land reclamation and higher lakefront levees, the land extending from the ridge to the lake was developed by the mid-20th century, and the entire area popularly came to be known as Gentilly.

Some of the neighborhoods included in Gentilly include Dillard, Filmore, Milneburg, Mirabeau Gardens, Oak Park, Vista Park, Edgewood,Gentilly Terrace, Gentilly Heights, Gentilly Woods, Pontchartrain Park, Lake Terrace/Lake Oaks, Lake Terrace and St. Anthony.

Houses in both of these neighborhoods are offered in a wide range of prices. For example, a three bedroom, two bath home in Pontchartrain Park is $185,000 while a 2,000-square foot duplex in the City Park area is on the market for $569,000.