The autumn Chilterns Walking Festival will take place from 17th October to 1st November 2020. The programme includes over 40 guided countryside walks, activities and events including routes centred around nature reserves, iron age hillforts, farms, churches and filming locations. All led by knowledgeable guides and taking in the beautiful Chilterns landscape.
There are number around here.
See https://www.visitchilterns.co.uk/walkingfest.html for more detail.