E4 European long distance trail

The E4 European long distance path or E4 path is one of the European long-distance paths. Starting at its westernmost point in Portugal it continues through Spain, France, Switzerland, Germany, Austria, Hungary, Romania, Bulgaria and Greece to end in Cyprus. It also visits the Greek island of Crete

Its length is more than 10,000 km, but the route through Romania and part of Bulgaria is not yet completely defined. An alternative route through Serbia, instead of Romania has been defined.
(source: Wikipedia)