How big is the studio in the Truman Show?

Question

Coming to you now, from Seahaven Island, enclosed in the largest studio ever constructed and, along with the Great Wall of China^†, one of only two man-made structures visible from space, now in its thirtieth great year, it's The Truman Show!

_{Announcer, The Truman Show}

It contains a small town, a sea, land beyond the town. But Truman almost reaches its edge during his first attempted escape.

So how big is the studio?

Is there any source that gives a size, or does it come down to measuring and estimating?

---

^{† That the Great Wall of China is visible from space is a common misconception, here repeated by the announcer in the movie.}

Answer 1

Based on the images seen in the film, the dome is approximately 8.5-10 miles wide at its base.

Unfortunately, due to a slight foreshortening effect in the satellite image, it's not really possible to be much more accurate than that.