  Dynamical roughening of interfaces has received much attention in recent
years. However, experiments have been restricted to one dimensional (1d)
systems. Moreover, theoretical studies of the two dimensional (2d) case have
been highly inconclusive. Here we introduce an experimental 2d system, with
which the theories can be tested. As is shown, the surface of a 2d pile of rice
shows roughening behaviour in both space and time, with a roughness exponent
$\alpha_{2d}$ = 0.39(3) and a growth exponent $\beta_{2d}$ = 0.27(3).
