Marvel World Adventure Playset was a full-color die-cut cardboard playset put out by Amsco in 1975. Along with cardboard versions of such familiar Marvel sites as the Baxter Building and the Daily Bugle, the set came with 30 cardboard cut-out superheroes and villains.
I remember having one of these as a child. A mint-in-box version of one of these today goes for around $500.