Isn't this what treasure maps are for? You are digging and gathering and minding doing what you then bam here is the key to portal to where you can fight some dangerous monsters for loot. They called a treasure map and you can instance it at your leisure and you can even trade/sell the map. But if you did the map immediately and teleported to where it wanted you to go, it would be essentially this. Good luck if you meet a Chimera from peiste map.