"Tom Swift in the City of Gold; Or, Marvelous Adventures Underground" by Appleton is a novel published as Volume 11 in the original Tom Swift series. When Tom receives word of a legendary underground city filled with gold treasures hidden deep in Mexico, he sets off on a daring expedition. But he's not alone in the quest—his rival Andy Foger, a band of scheming Mexicans, and mysterious Head Hunters all compete for the ancient riches. Underground dangers and accidental entrapment threaten the adventure at every turn. (This is an automatically generated summary.)