  We present the ESO Distant Cluster Survey (EDisCS) a survey of 20 fields
containing distant galaxy clusters with redshifts ranging from 0.4 to almost
1.0. Candidate clusters were chosen from among the brightest objects identified
in the Las Campanas Distant Cluster Survey, half with estimated redshift
z_est~0.5 and half with z_est~0.8. They were confirmed by identifying red
sequences in moderately deep two colour data from VLT/FORS2. For confirmed
candidates we have assembled deep three-band optical photometry using
VLT/FORS2, deep near-infrared photometry in one or two bands using NTT/SOFI,
deep optical spectroscopy using VLT/FORS2, wide field imaging in two or three
bands using the ESO Wide Field Imager, and HST/ACS mosaic images for 10 of the
most distant clusters. This first paper presents our sample and the VLT
photometry we have obtained. We present images, colour-magnitude diagrams and
richness estimates for our clusters, as well as giving redshifts and positions
for the brightest cluster members. Subsequent papers will present our infrared
photometry, spectroscopy, HST and wide-field imaging, as well as a wealth of
further analysis and science results. Our reduced data become publicly
available as these papers are accepted.

Astrophysics