Unless it is a natural occurance (landform, vegetation, etc.) that creates the separation, isolated holes tend to future topagraphy and landscape that fails to flow or tie into their surroundings.
I can think of numerous times at Sunningdale last summer where you see other holes. In some cases you have to cross other holes from green to tee.
I think the intermitent openess of a golf course is key. Tom mentioned the 3rd/13 at Pacific Dunes; a similar scenario occurs on 4 at Bandon Dunes. The experience from the landing area as you turn toward the green, and on as you walk to the green and look up 5, and on to 13 at Pacific and South to 12, 15, 16 and Bandon. for people who visit the first time, this is where their experience goes from "cool", to "awsome"!
Great landscape design, think Central Park and the like, is all about moving people through different spaces without people consiously knowing it. With golf design, the great golf courses do the same, sometimes with individual holes, a sequence of holes, or even with parts of holes.
Interesting reading this being on site at our project in South Korea. We have faced many "Rules" or "Preferences" here, that we have been trying hard to break or pursuade otherwise. It seems as though in Korea they tend to prefer or think of golf holes like individual rooms. They like to use large transplanted trees to make "curtains" rather than clustering trees in semi random yet appropriate locations that break up holes and areas of the golf course and preserve views and vistas from one hole to another and accross the greater landscape. After hearing members of the design and construction team talk about the open floorplans for their clubhouse and villas, I have adopted the phrase "open floor plan" for use on the golf course.
The great architects wither embraced the elements of their sites that created this scenario, or were able to manufacture it without it being painfully obvious.