Scaled down Neuschwanstein could be a volcano green site, Palmanova an island green and Crac de Chevaliers a peninsula green.
But these are the more obvious examples. It's more hidden, less obvious examples I'd prefer to focus on.
Aspects like frontal defences, weak points, optional entry points, angles, water retention, drainage etc.
There are maybe some lessens to be learnt from fortifications as well ..... how gun powder and trajectory, the aerial golf game of the time, made many a fortification undefendable. Bit like how some greens designed during the era of the ground game play in the current era of high trajectory shots with spinny balls and irrigation.
Another comparison could be with beautification. How fortifications morphed into gorgeous buildings. Bit like golf courses with flower beds and fountains.
atb