There are 500 plus one day walks described on the Where2Walk website. To make it easier to find the walk suiting you best they have been separated in to categories (short walks, historical walks, mountain walks etc:).
Away from the individual Day walks (which form the bedrock of the website) there are other types of walks including:
Where2Walk believes that everyone should be able to read and use a map of the area you plan to walk in and therefore be able to take responsibility for themselves. They offer 1 or 2 Day Navigation Courses to help. Alternatively Hire a Guide for the day.