  Dwarf galaxies are crucial to understand the formation and evolution of
galaxies, since they constitute the most abundant galaxy population. Abundance
ratios and their variations due to star formation are key constraints to
chemical evolution models. The determination of these abundances in the dwarf
galaxies of the Local Universe is thus of extreme importance. However, these
objects are intrinsically faint and observational constraints to their
evolution can be obtained only for very nearby galaxies. NGC 185 is one of the
four brightest dwarf companions of M31, but unlike than the other three, NGC
147, NGC 205, and NGC 221 (M32) it has an important content of gas and dust. We
obtained deep spectroscopic observations of the H$\alpha$ emitting population
of NGC 185 using GMOS-N at Gemini. As a result, in addition to the bright
planetary nebulae (PNe) previously found in the galaxy and reported in the
literature, we found other, much fainter, PNe. We then re-calculated the
electron temperatures and chemical abundances of the brightest ones, and
derived, for the first time, their electron densities. Our characterisation of
the PN population properties is interpreted in terms of the chemical evolution
of NGC 185, which suggests that it has suffered a significant chemical
enrichment within the last $\sim$8 Gyr. We also discovered the first symbiotic
star in the galaxy and enlightened the properties of a known supernova remnant
located close to the centre of NGC 185.
