Dallas · Texas
A Fair Park guided tour typically lasts 60-90 minutes and involves walking the grounds of this massive 277-acre historic site. You'll see the Art Deco buildings from the 1936 Texas Centennial Exposition, the midway area, and a few museums from the outside. Expect a mix of history about Dallas's growth, Texas state fair trivia, and architecture details. It's mostly outdoors on paved paths, so you'll get a decent overview without entering any attractions. Groups are usually small to medium and move at a leisurely pace.
The best time to go is spring (March-May) or fall (September-November) when the weather is mild and crowds are lighter outside of fair season. Summers are brutally hot, and taking the tour during the State Fair of Texas in late September to mid-October means heavy crowds and parking headaches. Expect to pay around $15-30 per adult depending on group size and whether it's a private or public tour; kids are usually cheaper.
Pick a morning tour to avoid the Texas sun. Skip it if you're short on time or mainly want to visit specific museums inside the park - you can easily explore the grounds on your own with a map. The tour is most useful if you want context for what you're looking at rather than just taking photos.