The main Hill Valley town square scenes were filmed on the backlot at Universal Studios, Los Angeles. The set wasn't built for the film, but had in fact been built decades earlier, and used on countless movies and TV shows. Click here for an introduction.
There have been hundreds of movies and TV shows filmed on the Universal Studios backlot over the years. Want to know what other shows you may have seen the Courthouse Square in? Click here to find out. You may be surprised!
Okay so Hill Valley was supposed to look like an average American small-town, which means that there must be American small-towns that look like Hill Valley, right? Or maybe you want to get a photo of yourself in front of a building which looks like the clock tower? Find out more here.
Here is a 360 Degree view of the square (Quicktime File). This is from the Universal Studios website.
The set plans on the Universal website are quite out of date, but that's good because it means that the set is how it was in the BTTF movies! Get the plans here...
See Patrick Viney's incredible 3D model of 1955 Hill Valley here. Thanks also to Patrick for the individual 'plans' links above.