  CCD photometry on the intermediate-band uvbyCaH-beta system is presented for
the old open cluster, NGC 6253. Despite a high level of field star
contamination due to its location toward the galactic center, combination of
the data from the multiple color indices with the core cluster sample derived
from radial star counts leads to the identification of a set of highly
probable, single cluster members. Photometric analysis of a select sample of 71
turnoff stars produces a reddening value of E(b-y) = 0.190 +/-0.002 (s.e.m.) or
E(B-V) = 0.260 +/- 0.003 (s.e.m.) from 71 stars. The metallicity indices,
delta-m1 and delta-hk, both identify this cluster as the most metal-rich object
studied on either system to date. Simple extrapolation of the available
metallicity calibrations leads to [Fe/H] ranging from +0.7 to +0.9. Metal-rich
isochrones with overshoot imply an age between 2.5 and 3.5 Gyr, with an
apparent distance modulus between (m-M)= 11.6 and 12.2, depending upon the
isochrones used. The improvement in the fit using alpha-enhanced isochrones may
indicate that the cluster [Fe/H] is closer to +0.4, but the photometric indices
are distorted by an elemental distribution other than a scaled solar. The
galacto- centric position of the cluster, in conjunction with data for other
clusters and Cepheids, is consistent with the inner disk reaching and
maintaining a metallicity well above solar since the early history of the disk,
unlike the solar neighborhood.
