Mount Hiei
Refers specifically to the mountain located northeast of Kyoto, historically significant as the site of Enryaku-ji temple.
See also: 南山
Hokurei is another name for Mount Hiei.
Enryaku-ji (Tendai monastery on Mount Hiei)
By extension, refers to the Enryaku-ji temple complex itself, often in historical or religious contexts.
See also: 南都
Hokurei is the head temple of the Tendai sect.