It's not every year or even every decade that a major new theme park by an industry leader opens in the United States. Yep, after a major wave of expansion around the New Millennium (creating Animal Kingdom, Islands of Adventure, and California Adventure), Disney and Universal have gone pretty silent on the domestic theme park front... until now.

There's not a theme park enthusiast alive today who doesn't know about Universal Epic Universe – the celestial third gate en route to the ever-expanding Universal Orlando. Though Universal's technically been mum about what this otherworldly theme park will include, we've taken a look at its thrilling Celestial Gardens hub, and then passed through the four inter-dimensional portals leading guests into immersive lands themed to Fantastic Beasts and Where to Find Them, Harry Potter, How To Train Your Dragon, Universal Monsters, and of course, Super Nintendo World.

But even as fans online track every development of the brand new park that just might shift the gravity in Orlando for good (the numbers are already leaning in Universal's direction...), there's a selfish, lingering question out there: what's next? 

As theme park insider @TommyHawkins illustrated beautifully in an early (and so far, accurate!) look at what insiders expect Epic Universe to entail, both major and minor expansion pads exist all around the park – from single-acre spots where a flat ride or restaurant could be built onto an existing land, to a 20-acre zone that could fit Galaxy's Edge and Avengers Campus combined... So if Epic Universe is the smashing success most industry enthusiasts expect, then it's worth talking about a "Phase II" of this multi-billion-dollar park and which new portals may power-up before we know it...

1. Middle Earth: The Realm of the Rings

J.R.R. Tolkien's epic fantasy adventure series The Lord of the Rings (and by extension, its legendary trilogy of film adaptations released in 2001, 2002, and 2003) remains of the few major, theme-park-able IPs that's left "out there," unclaimed and largely undeveloped despite how well it seems to align with the "Living Land" model. Given our recent look at how the films' remaining sets have become tourist attractions in their own rights, there's clearly a hunger to step into the high fantasy world of Middle Earth.

That's not to say theme park operators haven't tried. Disney allegedly began to woo the rights-holders to the Rings books and films in the 2000s, as a potential new addition to Animal Kingdom. Then, rumors suggested that the "Blue Sky" version of Epic Universe had a Lord of the Rings land before it was pared down to its current five-land layout. Part of the problem is that the rights to The Lord of the Rings are complex – split between Warner Bros.' New Line Cinema, the Tolkien Estate, Middle-Earth Enterprises, and now, Amazon Studios. But Universal made a similarly complex relationship work with Harry Potter, so it's possible!

In other words, if Epic Universe is a runaway hit, look for The Lord of the Rings as a serious contender for the large, 20-acre expansion pad set aside between Potter and the Starfall Racers coaster.

And that's not the only major IP that insiders say is a logical next step for Epic Universe...