  We study iPTF14hls, a luminous and extraordinary long-lived Type II
supernova, which lately has attracted much attention and disparate
interpretation. We present new optical photometry that extends the light curves
until more than 3 yr past discovery. We also obtained optical spectroscopy over
this period, and furthermore present additional space-based observations using
Swift and HST. After an almost constant luminosity for hundreds of days, the
later light curve of iPTF14hls finally fades and then displays a dramatic drop
after about 1000 d, but the supernova is still visible at the latest epochs
presented. The spectra have finally turned nebular, and the very last optical
spectrum likely displays signatures from the deep and dense interior of the
explosion. The high-resolution HST image highlights the complex environment of
the explosion in this low-luminosity galaxy. We provide a large number of
additional late-time observations of iPTF14hls, which are (and will continue to
be) used to assess the many different interpretations for this intriguing
object. In particular, the very late (+1000 d) steep decline of the optical
light curve, the lack of very strong X-ray emission, and the emergence of
intermediate-width emission lines including of [S II] that likely originate
from dense, processed material in the core of the supernova ejecta, are all key
observational tests for existing and future models.
