You can only delete all of them, and the process might be different for different models.
On my "XL" (different from the "ONE XL") and on newer models, you just go to Navigate to... / Recent destination and there's a button at the bottom labelled "Delete".
If you don't have that button, then a Factory reset (from the preferences menu) or deleting the file "MapSettings.cfg" from your region's map folder will do it, but will lose all your other personal settings too.
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