There are four passes leading into their country; one through Sarapana, a Colchian stronghold, and through the narrow defiles there. Through these defiles the Phasis, which has been made passable by one hundred and twenty bridges because of the windings of its course, flows down into Colchis with rough and violent stream, the region being cut into ravines by many torrents at the time of the heavy rains. The Phasis rises in the mountains that lie above it, where it is supplied by many springs; and in the plains it receives still other rivers, among which are the Glaucus and the Hippus. Thus filled and having by now become navigable, it issues forth into the Pontus; and it has on its banks a city bearing the same name; and near it is a lake. Such, then, is the pass that leads from Colchis into Iberia, being shut in by rocks, by strongholds, and by rivers that run through ravines.