Diagon alley is basically the wizarding shopping mall. You can get anything here, from school books to magic wands.
The Leaky Cauldron Pub and Inn - The Entrance to Diagon Alley
Inside The Leaky Cauldron
"Welcome, Harry, to Diagon Alley!" -Rubeus Hagrid
Ollivander's Wand Shop
Entrance to Knockturn Alley
Knockturn Alley
Borgin and Burkes
Gringotts Wizarding Bank
Gringotts Vaults