D23 Expo's Theme Parks and Resorts panel confirmed that Guardians of the Galaxy: Mission Breakout, an attraction that opened earlier this year, is only the beginning of an expanded Marvel presence at Disney's California Adventure Park.

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Bob Chapek explained that fans can expect to see attractions based on Spider-Man and The Avengers, and assured the audience of 7,000 people that Disney's imagineers are hard at work on creating an "immersive" experience for Marvel fans, but could not elaborate further at the time.

The expansion of Marvel's presence in the parks was very subtly teased with a mysterious Avengers-branded hatch in the grounds outside of Mission Breakout -- but the actual role and symbolism of the hatch itself wasn't elaborated on during the panel.

The new Guardians of the Galaxy ride was announced at Comic-Con International in 2016, along with a tease from Joe Rhode, Disney’s Imagineering executive, that the ride would just be the first step in a massive expansion for the park.

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“[The Ride] will be the first of a whole new universe in Disney California Adventure,” Rhode said. “All of this is happening as we speak.”