Prior to a usage of fal-tor-pan that rejoined Spock's body with his katra in 2285, a Vulcan procession moved his katra-less body through the hall, exiting to an exterior portion of the temple. (Star Trek III: The Search for Spock)
Background information Edit
The name of this building comes from the screenplay for Star Trek III, as it is unnamed in the film. The area is often mistakenly referred to as the "Hall of Ancient Thoughts", though the script shows that it was actually the Hall of Ancient Thought.  On one occasion, the film's director of photography, Charles Correll, even referred to the site as "the temple of the Hall of Minds." (Cinefantastique, Vol. 17, No. 3/4, p. 52)
The hall is featured more in the script for Star Trek III than it is in the actual film. In the scripted version of a scene set in Spock's quarters (a scene that is mostly in the movie), the hall was referenced by Leonard McCoy while mentally affected by Spock's katra; the essentially possessed McCoy pleaded for Kirk to take him "through the hall of ancient thought." As they and their companions headed from the remains of Planet Genesis to Vulcan later in the script, Saavik told Kirk that the usual katra ritual deposited katras in the hall, warning him that fal-tor-pan would be far different from that common katra ritual. Even though the film's final version does not include the hall's interior, it was scripted to appear in a series of shots while the procession moved Spock's body through the hall. A scene description of the hall characterizes it as "lined with massive heads of stone."  These heads were intended to represent notable philosophers and scientific thinkers from Vulcan history, and it was planned for them to be lit by cauldrons of fire or balls of flame.
The area was designed by illustrator Tom Lay. (Cinefantastique, Vol. 17, No. 3/4, p. 68; The Making of the Trek Films, 3rd ed., p. 53; Trek: The Unauthorized Story of the Movies, p. 101) Industrial Light & Magic did some concept paintings of the hall's interior. In fact, ILM art director David Carson spent days developing alternative designs for inside the hall. A considerable amount of effort was also invested in the set, which was actually built. (Star Trek: The Magazine Volume 3, Issue 8, pp. 61, 54 & 60) The enormous heads were really photographic cutouts and were twenty foot tall. (Cinefantastique, Vol. 17, No. 3/4, p. 68; The Making of the Trek Films, 3rd ed., p. 53; Trek: The Unauthorized Story of the Movies, p. 101) They were created by J.C. Backings, by stretching canvas over a series of wooden frames. (Star Trek: The Magazine Volume 3, Issue 8, p. 61)
The scene showing the hall's interior was filmed. (Star Trek: The Magazine Volume 3, Issue 8, p. 61; Cinefantastique, Vol. 17, No. 3/4, p. 68) However, it was thereafter cut for time. (Cinefantastique, Vol. 17, No. 3/4, p. 68; The Making of the Trek Films, 3rd ed., p. 53) David Carson remarked, "The Hall of Ancient Thoughts actually became the Hall of Nothing, because it was too expensive." Director Leonard Nimoy and his producers also felt that the hall was not essential to the story. Even ILM's Nilo Rodis had reservations about the location, disappointedly believing that the set did not look anywhere near as impressive as it had in the concept artwork. "It didn't look that dynamic; it was a great concept, but when it was finally put together it just didn't feel magnificent," said Rodis. "There was just too much detail, and that took away from the meaning of the scene." (Star Trek: The Magazine Volume 3, Issue 8, pp. 54 & 61) Accounting for the deletion, Charles Correll stated, "The audience was starting to get ahead of them at that point." (Cinefantastique, Vol. 17, No. 3/4, p. 52)
The Hall of Ancient Thought was referenced in several Star Trek novels, such as The Lost Years. According to those books, thousands of receptacles (vre'katra) containing the katras of the greatest and most powerful Vulcan masters throughout history were housed in the hall, and Vulcan scholars, philosophers, and mystics could petition to be permitted to meld with these katras for research or enlightenment.