Revealing: In a few UNIT stories you can see where BBC TV badges have been on the UNIT land rovers

Continuity: When Ian and Barbara enter the TARDIS for the first time, Susan operates the door switch. Later on, when the Doctor electrocutes Ian, he uses the exact same switch.

Factual error: The tribe that Doctor Who meets is definitely Caucasian in appearance, which rules out Asia and the Americas as possible locations. Modern humans didn't reach Europe until around 30,000 years ago, so the date implied by the title is wrong. Also, the tribe is definitely NOT Neanderthal, as they apparently didn't have a tribal system.

Revealing: Susan is supposed to be running through a forest. It is painfully obvious that, in fact, she is simply running on the spot against a back-projected film, and the branches that hit her are simply studio stagehands, hiding just out of shot, hitting the actress with twigs.

Plot hole: When Ian is trying to escape from the Tardis in episode 1, he says, "He closed the door from over there, I saw him." Although it is in fact Susan who closed the door.

Revealing: During the long continuous hand held shot of Ian and Barbara exploring the junk yard in episode one, the cameraman trips, making the image jump up and down.

Visible crew/equipment: The boom mic makes an quick appearance about 18 minutes into episode one. It is in the upper left corner when the camera switches from a close up of the Doctor and Susan to a medium shot of all four characters.

Visible crew/equipment: About 90 seconds into Episode Two, the shadow of the boom mic crosses Ian's face.

Visible crew/equipment: The boom mic shadow makes an apperance in Episode Two, moving across the console as the Doctor suggests abandoning Barbara.

Revealing: In episode one, when Ian notices the breeze, a wide shot of the forest shows the background dropcloth is moving.

Revealing: In episode six, Ian helps Barbara get a grip on the rock and piece of the polystyrene pops off in his hand.

Revealing: In the Dalek city, it is unfortunately obvious that the "tunnels" behind the actors are just photographic blow-ups, as you can see the bottom of the wall meeting with the floor.

Continuity: In episode three, Temossus claims the Thals have been travelling for four years. But in episode five, Ganatus claims it is one year.

Revealing: Toward the end Episode Two, when Susan opens the TARDIS doors, the console wobbles.

Revealing: The supposedly heavy statue Ian drops down the lift to destroy the pursuing Dalek in episode four wobbles when he first touches it.

Revealing: There are numerous scenes where the background Daleks are blown-up photographs. The most obvious is in episode five when the Daleks are discussing the radiation drugs.

Continuity: The Dalek the crew ambush in episode three has a magnetic block in its sucker and, after the attack, a mud-covered eyestalk. At the beginning of episode four, the eye-stalk is visibly clear of mud, yet is later seen plastered with mud once more.

Revealing: When the Thals are using sunlight to blind the Dalek cameras in Episode Six, wide shots of the Dalek city show it moving back and forth from bad matte combination.

Visible crew/equipment: Toward the end of episode one, when Ian is wondering where Barbara is, the shadow of a boom mic moves over the door behind him.

Revealing: The Dalek that Ian hides from in Episode Seven has a bad castor. The flopping of one of its wheels is audible.