We present extensive UBVR photometry of the Galactic globular cluster ( GGC ) NGC 6712 obtained with the ESO Very Large Telescope ( VLT ) which reach down to two magnitudes below the main sequence turn-off and allows us for the first time to determine the age of this cluster .
By using the apparent luminosity of the zero age horizontal branch ( ZAHB ) , V _ { ZAHB } = 16.32 \pm 0.05 and the stellar main sequence ( MS ) turn–off ( TO ) magnitude V _ { TO } = 19.82 \pm 0.10 , we obtain \Delta V _ { TO } ^ { HB } = 3.5 \pm 0.1 ( a value fully compatible with that derived for other clusters ) which suggests that , at an age of \sim 12 Gyr , NGC 6712 is coeval with other GGC of similar metallicity .

We derive interstellar reddening by comparing the position and morphology of the red giant branch ( RGB ) with a wide variety of reference clusters and find E ( B - V ) = 0.33 \pm 0.05 , a value significantly lower than had been determined previously .
Assuming this value for the reddening , we determine a true distance modulus of ( m - M ) _ { 0 } = 14.55 , corresponding to a distance of \sim 8 kpc .

We find a population of 108 candidate blue straggler stars ( BSS ) , surprisingly large when compared with the typical BSS content of other low concentration clusters .
Moreover , we detect a very bright blue star in the core of NGC 6712 that might be a post-AGB star .
These results , combined with those already presented in two companion papers , strongly support the hypothesis that NGC 6712 was , at some early epoch of its history , much more massive and concentrated .
The continued interaction with the bulge and the disk of the Galaxy has driven it toward dissolution , and what we now observe is nothing but the remnant core of a cluster that once was probably one of the most massive in the Galaxy .