Foam superhero backdrop tutorial- lots of party ideas you can adapt for a superhero classroom!
MEHOFOTO Vinyl Photography Background Carton Superman Computer Printed Children Backdrops for Photo Studio
Superhero City - Inspired Posters, Batman (Gotham City), Superman (Metropolis), Spider-Man (New York City), Art Print Movie Series - 12 x 18
Popular items for superhero background on Etsy - Wallpaper Zone
heroes and villians birthday party - box city
Superhero City Skyline is High Quality non Toxic Eco Friendly Vinyl Wall Decal. A basic version can be found here