Idiom of the day :- A happy hunting ground

Usage, examples and definition of the Idiom :-

The North American Indians believed that when they died their souls would move on to a place where they would spend eternity happily fishing and hunting. However, when people speak of a happy hunting ground today, they mean an area rich in opportunities or one that will prove profitable to them. ‘I have discovered that the library is a happy hunting ground for my research work.’ ‘This beach is a happy hunting ground to anyone interested in collecting seashells.’