Key sequences were shot at Universal Studios Hollywood. Stage 12 was used for the balance chamber within the caverns at the climax of the film, as well as the massive treasure room flooded cavern set. This set was built inside the 140,000 gallon tank and had four submergible pumps flooding the set with 1100 gallons of water per minute through six ports.

The so-called 'sparkling cavern' with 3 massive waterfalls was constructed at the Falls Lake tank (see photos of the set in daylight). The set took nine weeks to construct, and featured an elaborate pumping arrangement that created the illusion that there was more than the 45,000 gallons of water per minute that was actually used.

The enclosed chamber in which the characters almost drown was also shot in the tank at Falls Lake - the metal-framed set was repeatedly lowered into the water from a large crane. To stop daylight ruining the atmosphere, the whole area was draped in black material.

New York Street was also used for the opening sequence of the movie set in 1865.

The entranceway to the caves and first cavern, along with the Mount Vernon cellar set was built on Stage 2 at Walt Disney Studios in Burbank.

Links:

• IMDB entry
• Official Website
• Wild About Movies interviews