When visiting The Port we could find the secret of 7 rox trees, three of them slightly concealed. Very enjoyable to be a premium member because I can collect rox more faster and much.
The trick shake every tree and wait for rox fell to the ground, then take rox as soon as possible before taken by another monster who happens to pass in front of the tree. If late to do that you will get small rox points.
Here 7 rox trees from left side scrolled to right screen: