I usually take what I call “hiking shoes” – they’re like hiking boots but stop at the ankle like tennis shoes.
For the Immersion and Redoux tours, there are castles and parks that include a fair amount of walking outside. It is usually paved (but sometimes could be gravel paths, grass or dirt/mud) and usually wet. So you would need water proof shoes with good traction. Traditional, over the ankle hiking boots are not really necessary for these tours but would be ok if that’s what you’re comfortable wearing.
For the Immersion Tour there is an optional walk in Glen Affric which would be a bit hilly, then there is also walking at the Culloden Battlefield (usually on a paved path), more walking in Clava Cairns (not paved) and walking around the Brochs. The village where Rent was filmed has a walk though the woods (above). My pictures are here: https://ahpinc.smugmug.com/CelticTime/Scotland/Outlander-Immersion/May312015 (Some things are different – there wouldn’t be filming where we saw it – but there may be filming somewhere else and we are stopping at a different location in Glen Affric – to name a few changes.)
For the Redoux tour, there is an optional walk out to Neist Point – the weather was too bad when we were there so we just saw it from the van and my group elected not to do the Fairy Pools which is a tramp through moors. So there is no hard core hiking, but it could be hilly and wet. My pictures are here: https://ahpinc.smugmug.com/CelticTime/Scotland/2018/Outlander-Redoux .
Here are some links to the places we didn’t walk to:
Neist Point: https://www.scotiana.com/walking-to-neist-point-lighthouse-on-the-isle-of-skye/
Fairy Pools: https://www.isleofskye.com/skye-guide/top-ten-skye-walks/fairy-pools
There are also some new places added to the Redoux for season 4 that I haven’t been to yet. Once I go, I’ll post more. 🙂
Note: The tours now aren’t exactly the same as when I first went on them – the pictures are just to show you the types of terrain you might find.