Thanks, I will try this the next time :)

when you import a new model as a building use the default Japanese Garden as your base. the park will then inherit the ability to terrain conform. also make sure you have plenty of extra edges in your model. the game can only deform your model on pre-existing edges in order to match it to the terrain where it is placed. more edges means smoother deformation. of course it also means more triangles, so its a trade off.

Nice! What's the setting I have to choose for my assets to adapt to height differences like this one?