  A significant fraction of ultraluminous X-ray sources appear to be embedded
in observable ionized nebulae that take the form of large, several 100 pc
diameter interstellar bubbles. Here we review optical observations of these
bubbles, their importance for our understanding of the nature of ULXs, the
energetics involved and their formation and evolution. Among the results
obtained are new arguments against conventional superbubble scenarios and
hypernova remnants, and we present the case in favour of ULX-wind/jet driven
bubbles. We report the discovery of new ULXs in very large SNR candidates in
nearby galaxies, and finally present an image of a triple X-ray source
coincident with the radio-bright bubble S26 in the galaxy NGC 7793 which
appears to be a clone of the microquasar SS433/W50 system.
