  [Abridged] We present results on the clustering og Lyman break galaxies
(LBGs) around a probable damped Ly-alpha absorption (DLA) line cloud at
z_DLA=2.974 from deep UBVI images of the field containing the quasar APM
08279+5255 (z=3.91). The large area covered by our images, 0.31 deg^2 or 40x40
Mpc co-moving at z=3, and their depth (27.6 mag arcsec^{-2}), allow us to
identify 450 LBG candidates brighter than I(AB)=24.80 at 2.75<z<3.25. LBG
candidates were selected using photometric redshift techniques that include
priors within a redshift slice of width Wz=0.15 centered at z_DLA.
  Within that redshift slice, we find an enhancement of galaxies near the DLA
using both the surface density and an estimator of the 3-D spatial
over-density. The surface overdensity (3\times) is significant at the >95%
significance level on scales 2.5<r<5 Mpc co-moving and imply that some DLA
could reside in high density regions.
