Could we find a tree we know was planted in say 300 AD, then count the tree rings in its trunk? Or some kind of river that floods yearly and leaves a discrete layer of sediment?
That's dendrochronology, and it is used to date wooden objects. The problems are that you only get an age (the tree was N years old at the time this object was created), and that you only get a slice of the tree (you can only see the subset of rings that are visible in the wooden beam supporting the house).
You can compare ring widths, assuming you have wood from the same climatic area, and use that as a standard candle to date objects reasonably well.
