In north America there is a ruin which was actually was the city of gold. Well here is the story about it.
Once there was chief who was the leader of the city. He was very cruel and selfish. One fine day someone made a creation which would turn anyone or thing into gold. The chief used the machine himself and he was turned into gold.
The people in the village drowned him in water and yet the man turned the city into gold. Hence there are some rumors that say that there are 1 million or billion gold under the sea.