Studios:
* New Zealand's Stone Street Studios: This was the primary studio location, where many of the interior sets, as well as some exteriors, were built.
* Other studios in New Zealand: Smaller studios were also used for specific scenes.
On-location:
* New Zealand's diverse landscapes: The films heavily utilized New Zealand's natural beauty, capturing breathtaking scenes in mountains, forests, caves, rivers, and beaches.
* Other locations: A few scenes were filmed outside of New Zealand, including some in Iceland and Argentina.
While the majority of the film was shot on location, studios played a crucial role in creating the elaborate sets and special effects required for the fantasy world of Middle-earth.
Therefore, the answer is that the Lord of the Rings trilogy used both studios and on-location filming extensively.