Dubrovnik Riviera, a picturesque area lying along the gentle and rocky coast, with a mixture of pine, olive groves, and fine vineyards. Besides beautiful nature, here you can find the longest stone walls in Europe. Pelješac is the longest of all Dalmatian peninsulas, abounding in natural bays, mostly covered with woods, with a coast full of beaches, reefs, bays, and fjords. Where hills merge with a fertile valley, where a green river and mystical swamps combine with a clear blue sea, there is Neretva valley and Metković. The island of Korčula is the sixth-largest Adriatic island, stretching nearly 47 km (29 mi) in length. Rich in vineyards, olive groves, small villages, and a glorious old town.