HST image (F475W, F606W and F814W combined) acquired by Momany et al. (2005) observations, showing the SagDIG H II region. The left panel shows the location of the old stellar population marked with yellow squares. The right panel shows the young stellar population marked with cyan circles. In both panels, the vertical diffuse column density is indicated with the red arrow. The source in the upper right region is a foreground star.