While the recent fire at Notre Dame is certainly sad news, the stories about Jesus’ actual crown of thorns being located there deserve at least some scrutiny.
Many churches throughout history have claimed to be in possession of such “sacred relics” and very few ever take the time to verify those claims.
The sixteenth-century reformer John Calvin did and published his findings under the title: A Treatise on Relics
Below is his report in the “crown of thorns” and we hope that his admittedly satirical conclusion delivers many from gullibility, superstition, and idolatry.
With regard to the crown of thorns, one must believe that the slips of which it was plaited had been planted, and had produced an abundant growth, for otherwise it is impossible to understand how it could have increased so much.
A third part of this crown is preserved at the Holy Chapel at Paris, three thorns at the Church of the Holy Cross, and a number of them at St Eustache in the same city; there are a good many of the thorns at Sienna, one at Vicenza, four at Bourges, three at Besançon, three at Port Royal, and I do not know how many at Salvatierra in Spain, two at St James of Compostella, three at Albi, and one at least in the following places: Toulouse, Macon, Charroux in Poitiers; at Cleri, St Flour, St Maximim in Provence, in the abbey of La Salle at St Martin of Noyon, etc. 
It must be observed, that the early church has made no mention of this crown, consequently the root that produced all these relics must have grown a long time after the passion of our Lord.
Footnote by Calvin: “If a diligent inquiry were instituted after these relics in particular, four times as many as are here enumerated might be found in other parts.”