As Les Brass said - the South West Coastpath in the UK is amazing! 630 miles of stunning seascapes, red cliffs, rolling green hills and quaint thatched pubs serving ale and good food. There are campsites, B&Bs or inns to stay in - or wild camp as we do. Dogs are always welcome along the way. But be aware - we may not have as high mountains as Spain - but we do go straight up - some of the paths would make a goat wince! We are happy to welcome any sofa-surfers from this forum - we are 2 miles from the route (as long as we are here!!)
Another beautiful route that meanders across Britain from the salt-caked south west, through the heart of England and across to the heavenly countryside of Anglia, is the Mary Michael Pilgrim's Way. It passes through ancient sacred places, both pagan and Christian, such as St Michael's Mount, Glastonbury and Bury St. Edmunds, as well as many Holy Wells, standing stones and long-forgotten shrines. The sections from Land's End, Cornwall, through to Glastonbury are now signposted, but many have travelled the whole route on foot or horseback.
http://marymichaelpilgrimsway.org/route/ I helped with the pilot section and am walking the route in chunks and am happy to answer any queries.
We are not always lucky with the weather in the Uk - but it does mean we have a particularly verdant landscape - there are spectacular walks/cycles in most parts, but areas that stand out are: the Lake District, Scottish Highlands, The South Downs, Dartmoor and Northumbria.
We finished our (peculiar!) pilgrimage at Roslin Chapel near Edinburgh, Scotland. This meant cycling the whole east coast of England and we were stunned at the variety and beauty of the landscapes we travelled through. Perhaps a walk or cycle around the entire British coast would be in order...
(Tinkatinker - we spent our first night of the Uk leg of our pilgrimage at Glynde, wild camping by the river, we missed the Trevor Arms - but did sink a couple at The Snowdrop in Lewes...!)