For some, a map can be as interesting to read as a book (seriously) though considering most of the books on the top 10, this includes the map’s key as well as the bar code.
You could do worse than buy any one of the Harvey BMC mountain maps which seem to be available for most of the more popular walking areas by now. Something like Knoydart or Torridon for the walker who’s always dreaming of Scotland and looking for an excuse to get there.
There’s the usual Snowdonia and Lakes as well, but the gift has to be getting someone walking in a new area and perhaps South Snowdonia?
Getting into the more remote walking south of the border, in Wales it would have to be a map of the Cambrian Mountains, or more specifically the Elenydd. In England, then in order to get remote you need to get up into the Northern Pennines and Northumberland.
While that’s all mountain walking, you could look at the coastal areas and plant the idea of exploring some unknown shore into their minds. Harveys do a long distance footpath series, which could well inspire someone to finally walk that trail this year.
The options here are vast and don’t need to be limited to the UK. A couple of my choices would be MacGillycuddy’s Reeks with a promise of a few weekend trips in order to make use of the map or, looking further afield the Pyrenees would be something to aspire to.