Caravans could require a large investment in goods and camels. They were a rich target for bandits. The profits from a successful trade journey could be great. Many rulers along important trade routes created caravanserai (way stations). These were places where caravans could refresh their animals and supplies can be replenished. However, the volume a caravan could transport was limited. For example, a caravan of 500 camels could only transport as much as a third or half of the goods carried by a regular Byzantine merchant sailing ship.