  In this paper we describe the survey design for the Ultradeep NIRSpec and
NIRCam ObserVations before the Epoch of Reionization (UNCOVER) Cycle 1 JWST
Treasury program, which executed its early imaging component in November 2022.
The UNCOVER survey includes ultradeep ($\sim29-30\mathrm{AB}$) imaging of
$\sim$45 arcmin$^2$ on and around the well-studied Abell 2744 galaxy cluster at
$z=0.308$ and will follow-up ${\sim}500$ galaxies with extremely deep
low-resolution spectroscopy with the NIRSpec/PRISM during the summer of 2023.
We describe the science goals, survey design, target selection, and planned
data releases. We also present and characterize the depths of the first NIRCam
imaging mosaic, highlighting previously unparalleled resolved and ultradeep 2-4
micron imaging of known objects in the field. The UNCOVER primary NIRCam mosaic
spans 28.8 arcmin$^2$ in seven filters (F115W, F150W, F200W, F277W, F356W,
F410M, F444W) and 16.8 arcmin$^2$ in our NIRISS parallel (F115W, F150W, F200W,
F356W, and F444W). To maximize early community use of the Treasury data set, we
publicly release full reduced mosaics of public JWST imaging including 45
arcmin$^2$ NIRCam and 17 arcmin$^2$ NIRISS mosaics on and around the Abell 2744
cluster, including the Hubble Frontier Field primary and parallel footprints.

Astrophysics of Galaxies