People with advanced gold recovery knowledge have re-worked some old claims and recovered huge amounts of gold. As the land had already been mined, it actually made their job easier to move the earth for sluicing.
Gold will sometimes attach itself to big boulders.
Gold recovery also takes place in sunken ships and lost buried treasure. The Egyptians are famous for having pyramids and tombs with gold artifacts worth millions.
Recent events in the middle east have see modern looters trying to rob the museums and not the tombs. More mummies and tombs are still being discovered. In Egypt and other countries around the world. Space mapping by NASA has given the ability to "virtually strip" layers of vegetation exposing lost civilizations such as Angkor in Cambodia.
Many Spanish galleons still lay on the ocean floor undiscovered. Overloaded ships and bad weather sent many to the sea bottom. Tidal action and shifting sands can quickly bury the treasure. Modern ocean mapping with sonar are assisting gold seekers in finding lost treasure.
Personal and household electronics have gold used in their construction. Some companies will offer cash for your used electronics. They can use their gold recovery methods for a profit. Gold recovery from electronics is easier than the actually mining of gold. It is a much cleaner and friendlier environment. The gold has already been refined so its much more pure than raw gold.
Currently gold prices are very good and the exploration for gold continues to draw much interest. TV shows such as Gold Rush, Jungle Gold and Yukon Gold are very popular.