They have seen generations pass, the world change, and survived droughts and cold spells for a thousand years.
Yet, just as they did in the Middle Ages, Spain's millennium-old olive trees continue giving humans their green gold - a highly prized olive oil variety, which is now becoming popular as far away as Asia and the Americas.
Spain is rediscovering its ancient olive trees, which had been endangered by the advance of urbanisation and a search for more productive olive tree varieties.
The country's largest concentration of the ancient trees can be found in the north-eastern community of Taula del Senia - a grouping of 27 municipalities - where they number more than 4,600 in an area of 1,100 square kilometres.
“It is almost certainly the biggest concentration of millennium-old olive trees in the world,” Taula del Senia community manager Jaume Antich told dpa.
Trees of a similar age exist in Greece and Italy, but not in comparable numbers, he said.
Taula del Senia is also the only part of Spain where the trees continue to produce oil.
For an olive tree to qualify as being a millennium old, it needs to have a perimeter of at least 3.5 metres at a height of 1.3 metres from the ground. Some of the trees have a perimeter of more than 10 metres. Some are believed to be more than two millennia old.
For about a century, the number of ancient trees had been dwindling as farmers replaced them with more productive varieties. Millennium-old trees were also sold to private gardens as decorative elements - an uprooting which kills the vast majority of them within 15 years.
In 2009, Taula del Senia introduced a project aimed at reviving oil production from the “monumental trees,” for which the Environment Ministry contributed about 1.2 million euros.
The project included subsidies to olive mills and agreements with 52 restaurants which are now using the oil in the region, Antich explains.
As a result, the number of companies producing oil from the ancient trees has risen from one to eight, he said.
The olives are harvested by hand in the last week of October or the first week of November.
In 2010, the trees in Taula del Senia only yielded 6,250 litres of olive oil. In 2011, a drought reduced the production to a mere 1,000 litres.
The producers hedge their bets on quality rather than quantity. The millennium-old trees give an exclusive oil belonging to a variety known as farga, which has a mild and fruity flavour and fetches the hefty price of 30 euros per litre on the market. A bottle of ordinary, cheap olive oil can be bought for about three euros.
The oil from Taula del Senia has a life span of about 2 years, compared to just half a year for ordinary olive oil, Antich said.
A bottle of olive oil from millennium-old trees is now becoming a fashionable present in the same way as a bottle of fine wine, he said.
The oil has also begun to be exported to countries such as France, Italy, China, Japan, the United States and to Latin America.
“These trees have resisted everything,” Antich said. “They may live for another 500 or 1,000 years.” - Sapa-dpa