pom is basically a container of submodules, each submodule is represented by a subdirectory in the same directory as pom.xml with pom packaging.
Somewhere, nested within the project structure you will find artifacts (modules) with war packaging. Maven generally builds everything into /target subdirectories of each module. So after mvn install look into target subdirectory in a module with war packaging.
Of course:
$ find . -iname "*.war"
works equally well ;-).