Following a tip from from SL Newser, I'm now flying in a restored version of the soaring Lost Gardens of Apollo, a classic Second Life sim which went defunct around 2011, due in part to the real world housing crisis. It's now back under a new owner with a Linden Lab avatar name, and is listed as "The Lost Gardens of Apollo Historic Build". So if you haven't visited it before, or you have, and missed its absence, click here to see it in its new incarnation.
I've contacted Linden Lab and Apollo's original creator, Dane Zander, for details of this apparent acquisition. Dane did offer to sell it to the company five years ago, but reportedly got no offer then. (Linden Lab does occasionally buy great but defunct or soon-to-be-defunct sims, such as Svarga, the island ecosystem, so they can remain in-world.) And Apollo is definitely historic, created a full decade ago, years before mesh or fancy prims, its high towers and swooping lines showcasing Dane's great artistry building with basic primitives. (Below the break, what it looked like in 2006.)
Back in 2011, Dane described the labor (or maybe torture) of love he went through to keep it open as long as he did, without compromising its appearance -- a painful case study on the challenges of succeeding in a virtual economy driven by profit and consumerism: