The ancient history of the archipelago which is now Puerto Rico is not well known. Unlike other indigenous cultures in the New World (Aztec, Maya and Inca) which left behind abundant archeological and physical evidence of their societies, scant artifacts and evidence remain of the Puerto Rico's indigenous population. Scarce archaeological findings and early Spanish accounts from the colonial era constitute all that is known about them. The first comprehensive book on the history of Puerto Rico was written by Fray Íñigo Abbad y Lasierra in 1786, nearly three centuries after the first Spaniards landed on the island.