3d isometric style landscape hints

for a UO or D2 type look
can i get some suggestions on how to best represent the landscape?
just normal tri’s and quadtree method?
or a bezier patch?
anyone have some suggestions or links that will point me in the right direction?

i have done this with a quadtree + just normal squares with a landscape of 256x256 this seems to run fast enuf. though im not 100% sure if its the quickest way for a strictly isometric game