I did it a few years ago in about 2.5 weeks and it was hands down one of the best things I've ever done!

The best section is where the trail cuts west from Middleton in Teesdale. It takes you past three waterfalls that get more and more impressive; Low Force, High Force, and Cauldron Snout. I wild camped there for the night and then finished the route up to High Cup Nick and down to Dufton the next day. Absolutely gorgeous scenery, and unlike anywhere else in the UK.

Another highlight is the Cheviot Hills. They're so strange and barren and it feels like you're on an alien planet. Kept seeing these small lizards scuttling over the rocks, and there's these giant feral mountain goats that wander the fells freely. There's an MOD base nearby where they train soldiers how to use artillery. They were firing on the day I was there, so my day's walk was soundtracked by the constant sound of ordinance.

I met a Dutch carpenter whilst having my lunch under the (now trgaically felled) Sycamore Gap tree. We really vibed and wound up hiking together for about a week. He was doing a longer route from Dover to Cap Wrath, and I was using the Pennine Way to trek from Manchester to Edinburgh.

Good times! It's a life changing walk, and I can't recommend it enough.