The Greenwich Meridian Trail is a new long-distance walk from Peacehaven in East Sussex to Sand le Mere in East Yorkshire, following the line of the Prime Meridian. The total length of the trail is 273 miles (439 km). It is divided into four parts, this guidebook covers the first part which takes you through the lovely and varied countryside of southern England and a surprisingly quiet and 'green' way through the outskirts of London to Greenwich and the Royal Observatory. The guide uses ordnance survey maps for easy route finding and is full of information about the places you will visit and stay at along the way. Good access by public transport makes it easy to do the walk in sections.