Here's a little schema pic...
I will definitely want to have maps. The Walk Segments will have KML files which will need to be displayed on maps. Walk Towns will need to be as well, using the latitude and longitude values. I'll need to filter the walks by things like Country, Distance, Difficulty, #of days (total segments), Total elevation gain etc.
This site - https://www.inntravel.co.uk/holidays/walking-holidays - sells walking holidays. Their faceted search is similar to what I want, but I would like to have a map which shows the applicable walks when filtered. That site also doesn't have maps for the walks. (Thanks for that @dragan - it's definitely a good idea for me to have a better look at sites that are doing similar).
Heading over to check out the docs pwired suggested now.
Thanks!
Heather