Final answer:
Eight sound stages were used for filming The Hobbit series, which provided controlled environments for the diverse sets representing Middle-earth.
Step-by-step explanation:
During the filming of The Hobbit series, a total of eight sound stages were used at Stone Street Studios in Wellington, New Zealand. These sound stages allowed the filmmakers to create the diverse and complex environments of Middle-earth indoors, where they had greater control over the elements and could construct large, intricate sets. Using multiple stages was crucial to accommodate the breadth of the production, which included sets like Bilbo's house at Bag End, the goblin caves, and parts of the Lonely Mountain.