At the south end of the school lies the Southern Cross Tower, connected to the main buildings by a thin covered corridor. It was built to include the Astronomy and Divination classes, as well as provide a room for students of all houses to gather and socialise.
Rebuilt to house a more modern hospital wing, the centre was largely funded by the Tarnagulla family, who took over the school in the early fifties. The building was later extended again to accommodate classrooms, and dormitories.
In August 2011, Tallygarunga opened up this new wing in order to hold the classes for the new junior sections of the school. All classes from Prep to Grade 5 are held in here, and outside there are a couple of playgrounds around the building, fenced off from the senior Tally students (not that it would stop some).
The dry gardens of Tallygarunga, humming to the sound of native animals in the surrounding bushlands. Full of places to sit and relax, as well as a few out of sight areas where mischief is more than likely to occur.