now part of Gillingham Walkers are Welcome
The Balsam Centre run walks of varying lengths, up to approximately 5 miles. They have issued their Walks programme for the period to end of September 2017; the walks in blue may be of particular interest. http://balsamcentre.org.uk/downloads/Walks-brochure-Apr-to-Sept-2017.pdf
The BBC's Get Inspired website (previously "Things to Do") may list local walks and other activities:
Our Group has received an unsolicited approach from this group, asking if Gillingham walkers might be interested in travelling abroad to walk in Greece. Their website is http://www.greeceonfoot.com/index.html in case walkers would like to have a look for themselves.