The teeth and fingerbones of holy men and more
The Pool of (add the name of the God or Goddess of your choice) is well known as one of the greatest holy places of the world. It is said to be full of piles of gold and jewels, a place where wishes are granted, wounds are healed, prophets have dreams that come true, and suspected criminals are fairly judged. Pilgrims from the other end of the world have been known to travel for more then a year, braving the perils of disease, brigands and bad weather, just to reach it's holy waters.
When running a new party, get around the question of plot density by having the first discovery to be a deck of fate, or whatever you call it. If you use a real deck, you should definitely stack it to have the desired outcome, which is to curse the party to attract weird things to happen and involve them. This should not be told to the players at the time, so that they won't just up and try to get themselves 'decursed'. Though quite why they would want to is beyond me.