Import Project Or Module Wizard

From the Welcome screen (if no project is currently open): Import Project
File | New | Project from Existing Sources
File | New | Module from Existing Sources
From the Project Structure dialog: Modules |  | Import Module

Use this wizard to import existing sources into IntelliJ IDEA and, as a result, to create a new project (New | Project from Existing Sources) or to add a module (or a number of modules) to an existing project (New | Module from Existing Sources).