UKH

Without being particularly pedantic, the quality of this little write-up about the UK's National Parks is pretty poor. https://www.bbc.co.uk/newsround/46825073

Cairngorms home to the highest Mountain Range? 

Welsh Moutain Pomies of the Brecon Beacons?

Just 34 miles of cycle/walking track in the Peak District?

Wouldn't have got away with this in John Craven's day...

Not sure you are correct in pulling them up on the Ponies. There are quite a few Welsh mountain ponies in the Brecon Beacons. You can also find Welsh mountain ponies on the coast near Stackpole in Pembrokeshire, and on the Long Mynd in Shropshire as well as in the Brecon Beacons and the Carneddau.

"highest mountain range" (for Cairngorms NP) - the Cairngorms have the largest area of land over 1000m ASL  in the UK even if they don't have the highest point so there's some truth behind the statement, but its not clear & they should have done better

There are in fact more error's in your post than the BBC's article.

Nation Parks?

 Technically this is correct - It's the UK's largest area of high ground. 

Moutain Pomies?

 > Welsh Moutain Pomies of the Brecon Beacons?

What exactly are Moutain Pomies?

With regards to the Peak Cycling trails etc From the BBC page:

"It also has 34 miles of trails ideal for walkers, cyclists and horse riders."

if you add the High Peak, Monsal, Thornhill and Tissington together you get the 34 miles referred to.

And the park authority themselves state "In total we own and manage 34 miles of trail."

The article was pretty much as expected for these things, I didn't think it was too bad. Probably written by some staffer in London Village ( (c)1997 Mark 'n' Lard) who wouldn't be able to point to the Cairngorms on a map and who will have just copied some bits from Google or from some guff that the NPA attached to their email requesting the BBC do a piece about the 70th anniversary. 

On a couple of the specifics, the 34 miles of trails could well be something like designated or named trails, it's obviously not every FP or ROW (edit: clarified by Larefia at 11:55); the highest mountain range might have been misinterpreted from 'highest in a NP' or something similiar from the NP's info. I doubt if loads of people are going to go and climb Cairn Gorm and then be disappointed that they aren't on top of the UK.

You need to read about Muphry's law

Yep, Welsh mountain ponies are a thing - just like our Highland ponies are in Scotland.

I appeared on John Craven's Newsround once, steering a narrowboat into Stoke Bruerne!

Anglo-Welsh sheep who speak bad French and emigrated to Australia?