The first you may recognize from the Lord of the Rings movie trilogy (Web), the dramatic carved cliff faces near the waterfalls. While I don't have the talent to create the sculpts myself, I think I could make something similar. Maybe showing the work in progress so I could stick with prims that simply evoke the final image and lay out the trappings of a carver's worksite. Or make the sculptures more architectural, avoiding the human form entirely. Something like the carvings at Petra, in Jordan (Web), creating the facades of buildings or individual elements like columns. Another idea is to make something like the Arc de Triomphe in Paris (Web). The JD Mechanical Toy Factory in Second Life (SLurl) has a wonderful arch that could probably be adapted for such a purpose.
Maybe floating islands are a bit trendy, but the concept is really timeless, and as this picture shows, the reason everyone loves them is the magical beauty. I have a wonderful small castle from a builder that seems to no longer be in-world, but it would look great in this context. Likely I'd want to use some of it's construction details to replicate this specific image. And I'd need to add to the floating island sculpts that I have to make a "chunk" like this one, perfectly suited for the structure. The two blend beautifully, the castle being very site-specific so the two form an "organic" whole.
I have folders full of wonderful architecture art and photos, some having been ear-marked as possible projects in Second Life should circumstances and talent permit. But these two are very high on the list.