Believe me, I know how this looks.
But also this. Balloons and the Grand Palais go way back:
And anyway also this, Leviathan has a groin vault:
and is the venue for a concert performance by minimalist composer and maximalist stuffed animal shaman Charlemagne Palestine:
[image of Anish Kapoor posing in front of Leviathan via mymodernmet, as baited by starwarsmodern. Images of Charlemagne Palestine performance inside Leviathan via Monumenta 2011]