About 24km beyond Mach, after passing several coalmines, a rough track running right off the main road leads to Pir Gheib. This beautiful rock pool is fed by a cascade and is surrounded and enclosed by cliffs and trees. There's another pool with calmer waters slightly downstream. Near the pool is a small shrine to a saint. Foreigners need a special permit to come to both the shrine and Pir Gheib - for the latest details ask at the PTDC office in Quetta.
With your own vehicle, a day trip from Quetta is just about feasible.