Bones, skin, fingernails, toenails and possibly a kidney: Older Than Jesus. (Surely, DNA can and will be extracted.)
https://www.bbc.com/news/uk-northern-ireland-68092307
Radiocarbon dates of 2,000 - 2,500 ya are not so precise, really.
"Tollund Man, I." by Seamus Heaney, 1979.
Some day I will go to Aarhus
To see his peat-brown head,
The mild pods of his eye-lids,
His pointed skin cap.
In the flat country near by
Where they dug him out,
His last gruel of winter seeds
Caked in his stomach,
Naked except for
The cap, noose and girdle,
I will stand a long time.
Bridegroom to the goddess,
She tightened her torc on him
And opened her fen,
Those dark juices working
Him to a saint's kept body,
Trove of the turfcutters'
Honeycombed workings.
Now his stained face
Reposes at Aarhus.