In Ferrals-les-Corbières (Aude) there is a huge and incredible museum: the Spiktri Street-Art Universe. You can see hundreds of realisations. Most of them are from Spiktri but some are from others artists. A small part is visible from outside (so it's free). I only share about this part...

To know some more, you can look the website: https://www.spiktriartshop.com/