  The problem of time and the quantization of three dimensional gravity in the
strong coupling regime is studied following path integral methods. The time is
identified with the volume of spacetime. We show that the effective action
describes an infinite set of massless relativistic particles moving in a curved
three-dimensional target space, i.e. a tensionless 3-brane on a curved
background. If the cosmological constant is zero the target space is flat and
there is no ` ` graviton" propagation (i.e., $G[g_{ij} (2), g_{ij} (1)] = 0$).
If the cosmological constant is different from zero, 3D gravity is both
classical and quantum mechanically soluble. Indeed, we find the following
results: i) The general exact solutions of the Einstein equations are singular
at $t=0$ showing the existence of a big-bang in this regime and ii) the
propagation amplitude between two geometries $<g_{ij} (2), t_2| g_{ij} (1),
t_1>$ vanishes as $t \to 0$, suggesting that big-bang is suppressed quantum
mechanically. This result is also valid for $D>3$.
