Lumban, officially the Municipality of Lumban, is a 3rd class municipality in the province of Laguna, Philippines. According to the 2020 census, it …Lumban, officially the Municipality of Lumban, is a 3rd class municipality in the province of Laguna, Philippines. According to the 2020 census, it has a population of 32,330 people. Lumban, one of Laguna's oldest towns, is located 7 kilometres from Santa Cruz, 94 kilometres southeast of Manila, and 55 kilometres north of Lucena. It got its name from Aleurites moluccanus, a tree locally named "lumbang". The province's capital town, Santa Cruz, as well as Cavinti and Pagsanjan, were once part of Lumban. The town contains the river wherein the Laguna Copperplate Inscription was found. The copperplate is the oldest known document found in the Philippines, dating to 900AD.