Building castles and cities on untouched terrain is entertaining. Working your way around the landscape while maintaining the environment is a great creative way to build. Cant really enjoy flat land builds. The spruce forests are my favorite because of all of the mountains and hills scattered through.
If you can learn to build statues of various sizes and subjects, they make great additions to your world. Like large statues holding up your castle, or creating "ancient" stonework in random locations for detail.
