There are at least 3 ways to get to the castle: challenging, picturesque and easy.
I take the middle one: I follow wide curves up to the top for several kilometers. I watch the landscapes, listen to birds and do not get tired too much.
The challenging route I ecknowledge on my way back to Citta Alta. I pass along people who breath deeply and rest each several steps. But they are following this path:
The third way is more expensive but comfortable. Here is the upper station of Funicolare: