Gethsemane's oldest olive trees are popularly said to have witnessed the events described in the gospels, a claim that scientific dating has not been able to confirm quite that far back.
Old, but probably not that old
Scientific studies, including radiocarbon and ring analysis of several of the garden's ancient olive trees, have generally dated the oldest surviving trunks to several hundred years old, considerably short of the roughly two thousand years that would be needed to place them at the events of the gospel narrative. Because olive trees can regenerate from their own root systems even after a trunk dies or is cut, some researchers note the underlying root stock could theoretically be much older than any single visible trunk, though this remains difficult to verify directly.
What the gospels describe happening here
The gospel accounts describe Jesus praying in anguish at Gethsemane the night before his crucifixion, asking that his coming suffering be spared him while accepting it as necessary, before being arrested after Judas identified him to soldiers with a kiss, an episode that has made the garden one of the most visited sites associated with the Passion narrative specifically for this single, emotionally direct scene.
As this entry's companion article covers
The presence of multiple denominationally separate garden plots, each maintained by a different church and each presented to visitors as the authentic site, is addressed directly in this entry's companion article rather than repeated here.