Millenary olive trees: The Montsià plains of southern Catalonia are home to the world's largest concentration of millenary olive trees.
Ancient trees: More than 4,400 of these trees are thought to be more than 1,000 years old -- and many are still producing olives.
World's oldest?: Researchers at the Technical University of Madrid have found the Farga de l'Arión tree to be 1,700 years old. This makes it a strong contender for being the world's oldest olive tree.
Mar de Olivas: The region, shielded between two small mountain ranges, in a broad dry valley near the mouth of the Ebro River, is known as Mar de Olivas (Sea of Olives).
Heirloom olives: Because the Farga, an heirloom olive endemic to the area, is less productive than other varieties, it fell out of favor for many years.
Back in fashion: However, the growing popularity of the Mediterranean diet and increasing consumer interest in food provenance have opened up new opportunities for olive oil entrepreneurs.
Local producers: Around 10 local producers are now making their own brands of millenary olive oil. The Arión estate is also home to an open-air museum.
Moleta del Remai: The Ebro Delta and the Catalonian coastline can be seen from the clifftop ruins of the Iberian settlement of Moleta del Remei.
Ulldecona: The town of Ulldecona is dominated by a medieval castle -- pictured here lit up in the distance. The town has two Michelin-starred restaurants where you can sample millenary olive oils.
Ermita de la Pietat: Serra de Godall, a short distance from Ulldecona, is home to a hermitage church, Ermita de la Pietat.
Cave paintings: Along the stone wall to the left of the hermitage church at Serra de Godall, there are rock shelters decorated with ancient cave art.