Classic Doctor Who was a very different show to the one that's around today.
With vastly smaller budgets and less advanced technology, it obviously doesn't have the same high production values we've seen since the Whoniverse returned in 2005.
Especially in the earliest classic days, it was rare for scenes to be shot multiple times too. So, whatever you got on that initial take - warts and all - was usually what ended up in the final cut.
And don't think NuWho is off the hook! Even with a bit more money and the benefits of digital filming, there are plenty of errors that got shown on millions of TV screens every Saturday night.
Rather than focusing on simple mistakes like continuity errors, this list is all about those unintended touches that found their way into the background of Doctor Who episodes - things that were captured on camera that you were never supposed to see.
From equipment in the shot to some nosy members of the public, some of these are minor, some of these are major, but all of them are absolutely hilarious.
10. The Mystery Foot On Bad Wolf Bay
There are few moments more heartbreaking in all of Who history than the end of Doomsday, when Rose Tyler says goodbye to the Tenth Doctor from across parallel universes.
After the Doctor's message cuts out and he totally leaves her hanging, Rose runs back to her mother Jackie and embraces her in a tender moment. All while Mickey and Pete watch on, presumably with no idea how to navigate all this emotion.
But what you might not know is that there's someone else present in this scene.
Behind the mother and daughter, to their right, is the truck that they all arrived in. Right at the end of the hugging shot, a person's foot can briefly be seen stepping out from behind the rear tyre, before quickly moving out of view again, presumably after realising what they'd done.
Maybe they just wanted to run out and give Rose a hug. That's what everyone else watching wanted to do!