I have been pondering the best way to start off an OpenQuest game in my Alusia setting. And probably I should just put the player’s characters on a boat bound for the Alusian islands. But it also occurs to me that they have heard of the islands by getting their hands on an old pirate's treasure map showing the location of one of the ruined cities on the main island.
During the day the jungles on the main island are dangerous. Large wildlife, giant spiders and the like but at night the seemingly empty ruins start to see some activity from the serpent men.
The serpent men of the Alusian islands are the degenerated survivors of a vast magical empire that covered the globe back when humans were just learning to use tools. Now they live in some small pockets deep beneath the earth on the Alusian islands which used to be at the center of their empire.
The local islanders know it is unwise to travel on the islands that have serpent men ruins after dark. The serpent men are very jealous of protecting their cities.