The Thousand Écus (Les Mille écus in the original French) is a two page adventure in the Johan and Peewit comics series, written and drawn by Peyo and first published in 1957 in issue 1000 of Spirou magazine.
Peewit has taken to singing and playing a lute, but his loud and out-of-tune performances become too much for the King and Johan. Johan then comes up with a plan to get rid of the lute and play a trick on Peewit.
The next day the King sends Peewit on an errand to a local village. Peewit is on his way, playing his lute, when he meets an old man who offers him a map which will lead to a thousand écus (gold coins). In return for the map, the old man suggests he take Peewit's lute. Peewit is reluctant but agrees.
While Peewit sets off to find the treasure, the old man takes the lute to Johan and the King, who then presumably get rid of it! The treasure map is a fake that Johan came up with.
The map's instructions lead Peewit to a very steep cliff which he has to climb. Reaching the top, he then has to find a big wooden cross. The journey to the cross takes all night.
Having reached the cross, Peewit now has to count all the trees in a nearby wood. Because the trees are identical he keeps counting the same ones several times. It takes him two days to finally count all 3624 trees!
The number of trees indicates the number of paces that Peewit now has to walk from the foot of the cross. This walk takes him through thorn bushes and a river. Finally, after walking 3624 paces, he digs the ground and actually does find a chest containing a 1000 écus!
Delighted, Peewit spends the treasure on loads of musical instruments which he then uses to perform at the castle, much to the distress of the King and Johan who cannot understand what went wrong.