From a normal view, the terrain looks fine, but inside a flying vehicle, from top down view, the textures on the terrain completely show off the tile, how can I prevent this?
When you Add/Edit textures in the inspector, there are 2 values in the pop up box: Tile Size X & Tile Size Y . If you increase these the tile will be larger but it may still look like a tile depending on how large the terrain is and how high above it you are. You can also paint on top of the existing tiles to give it a more unique look across the map.