Location of different classes of massive stars superimposed on a greyscale representation of Spitzer 8 μm continuum data. The location of the Galactic Centre, Arches and Quintuplet clusters are given by green crosses. Given their displacement from the nominal location of the Quintuplet cluster we have also plotted the positions of the LBV G0.120-0.048 and the WN6 star qF353E even though they are not included in the census on Table A.1. Each panel covers ∼208 × 70 pc at a distance of 8 kpc.