This should be (probably) in the Playstation Home section, since a lot of people, including myself have no idea what you're talking about. (And people get surly when I say Home is full of freaks; there you have it, I've been vindicated).
Took awhile to understand the question but lol think I got it. The OP is asking where the "secret domed gameroom" is & how to get in the treehouse there. To get in the treehouse just use the ladder, as for the "secret domed gameroom" haha they got you like they did alot of us w/ the description, there is no secret domed gameroom. Sorry but what ya see there is what ya get, it's still a huge space w/ nice atmosphere tho so I hope you enjoy the space.
what the heck what space ?
It's called the Luxurious Tropical Paradise Beach Crib,.. it has a huge beach w/ a forest type area that has a big pond & treehouse,.. There was a public space w/ the same name but I don't think you could access the forest area in the public space. It's old lol most have forgotten about it since it wasn't really all that spectacular, tho as I said it is huge & the atmosphere is pretty cool
Yea Pistol, I thought it was a pretty nice space as well, not my favorite but I liked the beach & the size of it made it worth the purchase. lol the OP's "21 cent" part is referring to the 21st Century part in the description, that had me stumped too so I had to go re read the spaces description again.