Originally, Studios was built with 3 mid-size soundstages and support venues, a small SFX stage, the water tank, a scenic shop, costume shop, audio post facility, screening theatre and backlot street. There was also the residential street and the animation studios as part of the studio complex, which was a separately "gated" area within the Studios park. Catastrophe Canyon was built specifically for the tram tour, to make sure guests had an "experience" regardless of whether any filming was going on or an area was blocked from guest access (like the residential street being filmed on and not being accessible to the trams). There were food locations on each end of the studio complex and one in the center that were meant to be shared by cast/crew and guests so the park guests could get a glimpse of their favorite stars, although there were private dining areas so the cast/crew didn't have to eat in the public areas (or that was the idea behind it): the Brown Derby was located to give easy access as the VIP restaurant for meetings, and had the attached casual food service for walk up. On the opposite side was Studio Catering if you were working on the backlot. And the Commissary had a specific production access from the back side, as it and GMR abutted the production complex as well. (Most of the studios have a main commissary & executive restaurant, plus multiple smaller cafe/coffee bar/walk-up's scattered around the studio lots.) Behind the scenes were a few other production support facilities that were not guest accessible, as well as additional food service. The gate to the entrance to the Animation Courtyard was the "studio gate" that took you from the "public" guest areas into the production center, and now looks somewhat out of place. It's all radically different now, functioning solely as a theme park. There is a small group that still facilitates filming in/around the park, but the remaining facilities are 99% for show.
The original soundstages are now Toy Story and have been altered. The post production stage is now a combined Legend of Captain Jack and Walt: One Man's Dream. The Walt Disney Theatre is now Voyage of the Little Mermaid. Edit: Rob's right - Captain Jack is in the original "set warehouse" and One Man's Dream was the audio post facility. I forgot there was the little walk-thru after the stages attached to the audio building.
