While not everyone would recognize this as an olive tree, most of us understand the meaning of the phrase 'extending an olive branch,' long known as a gesture of peace and friendship. That sentiment of compassion, harmony, and wisdom is at the heart of UNESCO's World Olive Tree Day, created in 2019 and observed every November 26. The intent of the day is to bring attention to the resolution of conflict worldwide and to the preservation of the olive tree itself, like this one standing in front of the Temple of Concordia in Agrigento, Italy. The well-preserved, Greek Doric temple was built on what is now the south shore of Sicily, around 440 BCE. Olive trees are native to the coastal regions of the Mediterranean and are cultivated today in places with similar climates, like parts of California and Israel. About 90% of harvested olives are used to make olive oil, the quintessential ingredient in Mediterranean cooking.