The Laguna Copperplate Inscription (Tagalog: Inskripsyon sa Binatbat na Tanso ng Laguna, Malay: Prasasti keping tembaga Laguna) is the earliest known written document found in the Philippines. The plate was found in 1989 by a labourer near the mouth of the Lumbang River in Barangay Wawa, Lumban, Laguna. The inscription on the plate was first deciphered by Dutch anthropologist Antoon Postma.