Location from harry-potter-order-of-the-phoenix by
Harry's miserable Muggle home in Little Whinging, Surrey -- this year the site of the Dementor attack that starts everything. Two Dementors in a suburban alleyway, and Harry's world changes forever.
Harry spends the summer at Privet Drive in a state of furious isolation. The Daily Prophet smears him daily. His friends write letters that say nothing useful. Dumbledore sends no word. He listens to Muggle news reports hoping for signs of Voldemort's activity. He lurks under the Dursleys' windows. He picks fights with Dudley out of boredom and rage. Then two Dementors glide into the alley on Magnolia Crescent. Harry casts a Patronus to save Dudley -- and receives a letter from the Ministry expelling him from Hogwarts for underage magic in the presence of a Muggle. The expulsion is reversed. The hearing is scheduled. And Harry leaves Privet Drive with the Advance Guard, flying over London on broomsticks, heading for a house he's never heard of at a number that shouldn't exist.
A neat, unremarkable detached house on a street of identical houses. Trimmed lawn, clean windows, polished car. Harry's small bedroom upstairs. The alleyway nearby where Dementors attacked Harry and Dudley on a hot summer evening.
Also known as: Privet Drive, 4 Privet Drive, the Dursleys' house, Number Four