In 1971, 20th Century Fox experimented with an anthology documentary series whose title was sort of self-explanatory.
Circus ran for 2 seasons (1971-3), but to my recollection lasted maybe just 1 in the home market. Entertainer Bert Parks, better known then as the MC of the Miss America Pageant, was the tour guide, taking viewers to various locations around the world and in the US.
Let's take a look at a sample clip, shall we?
Back in the day, it was not uncommon for one of the biggest touring circuses, Ringling Brothers-Barnum & Bailey, to have a network special every year. Fox suits must've seen the ratings, and thought a weekly show could do the trick. Apparently, they forgot that the scripted drama, The Greatest Show on Earth, loosely based on Ringling Bros., lasted just 1 year for ABC.