Uzbekistan's best kept secret By Monica Whitlock BBC Correspondent, Uzbekistan Kampyr-Tepe, in southern Uzbekistan, was built at the time of Alexander the Great's empire and occupied for about 500 years until it fell into decline. The fortified city controlled a key route from central to south Asia Since it was discovered, a generation ago, it has been closed to the public because it stands in a sensitive and tightly guarded military zone, right on the Afghan border. The city perched on a high shelf of land - cut into clay walls that dropped sheer into the plains below. Caught in...