Complex sentence: The Endor scenes in "Return of the Jedi" were filmed in two Northern California locations and in the Redwood grove near the Skywalker Ranch in Marin County California (Muir Woods).
Split into simpler sentences: The Endor scenes in "Return of the Jedi" were filmed in two Northern California locations. The Redwood grove near the Skywalker Ranch in Marin County California and in (Muir Woods).