On some of my sites, the Content > Pages submenu is visible, even though the Pages module has never been installed. This seems to happen on sites that use EE 2.3 and Structure.
I wouldn’t mind it, except that it creates conflicts with Structure and throws SQL errors if I try to edit content after navigating to the Publish/Edit screen via the Pages sub-menu.
The issue seems to be resolved in newer installs, using EE 2.4 and Structure 3.2.2. In older installations, the problem can be resolved by uninstalling Structure, installing/uninstalling Pages, and re-installing Structure. (i.e. Running the Pages uninstaller clears the Pages menu from the Content area.)
However, for existing sites that have this issue, where I cannot reasonably nuke all of my Structure pages, it’d be helpful to know where in its core EE decides whether or not to show that menu, so I can try to get rid of it by some manual process.