  We present high-resolution images of the strongly bipolar planetary nebula
NGC 6537, obtained with Hubble Space Telescope and with the infrared adaptive
optics system on the Very Large Telescope. The central star is detected for the
first time. Using the multi-band photometry and constraints from the dynamical
age of the nebula, we derive a temperature in the range 1.5-2.5 10^5 K, a
luminosity~10^3 L_sun and a core mass M_c~0.7-0.9 M_sun. The progenitor mass is
probably in the range M_i = 3-7 M_sun. The extinction map shows a largely
symmetric, and compact dust structure, which is most likely a shell, located at
the neck of the bipolar flow, only 4 arcsec from the star. The dust shell
traces a short-lived phase of very high mass loss at the end of the AGB. The
dynamical age of the shell and bipolar lobes are very similar but the
morphologies are very different. The data suggests that the mass loss during
the ejection of the compact shell was largely spherically symmetric, and the
pronounced bipolarity formed afterwards. The dynamical ages of the bipolar
lobes and dust shell are similar, which is consistent with suggestions that
bipolar structures form in a run-away event at the very last stages of the AGB
mass loss. The inner edge of the dust shell is ionized, and PAH emission is
seen just outside the ionized gas. We associate the PAH emission with the
photo-dissociation region of the molecular shell.
