A few years back, NASA released a digital makeover of the moon landing footage, clearing up the poor quality of the imagery. The footage includes Neil and Buzz walking on the moon. Though these updated recordings have been out for a few years now, back in 2006 NASA revealed they had recorded over the original video of the landing.
The tapes were part of 20,000 tapes that were magnetically erased and re-used to save money. Wiping and reusing tapes, or even outright destroying footage, was pretty standard practice several decades ago. Doctor Who, for example, which has recently become very popular on the internet, is missing numerous episodes from the 60’s and 70’s for the same reason.
There are good copies of the tapes laying around, however, which is good. And the footage isn’t exactly lost, either. You can clearly view it on YouTube today.