We took our horses on holiday here for my daughters 21st birthday, the lady who runs it is now doing a 100 mile ride to the coast, you have to do it on the centres horses though.
http://www.stonetrailridingcentre.com/pennine-bridleway-trail-rides/ridetosea.htm
http://www.stonetrailridingcentre.com/pennine-bridleway-trail-rides/ridetosea.htm