The Holm Oak of Culla Nature · Culla, L'Alt Maestrat, Castellón Monumental holm oak located in the municipality of Culla, considered one of the most notable singular trees in the Alt Maestrat. Known as the Gran Carrasca, said to be five centuries old, it is estimated to be around five hundred years of age and has been officially classified as a monumental tree of the Valencian Community. Photo: Juan Emilio Prades Bel (CC BY-SA 4.0) What to see and do in Culla