Step by step...
From Pariska, walk towards the InterContinental and cross the bridge and river towards the metronome monument.
Keep left and keep on walking up the hill towards a pavilion, enjoying the incredible view along the way.
Keep on walking, sticking to the edge of the hill, always keeping left.
You will reach a park with playground, cross the small bridge.
Again, keep left and stick to the edge, walking till you reach a larger pavilion style building. (you will feel like you have lost your way because it's so quiet and untouristic, but you are on the right track).
Along the way, you may chance upon a small Julius Caesar monument by a small pond.
Walk along a large beautiful garden, passing an old terrace with domed window frames, as well as a metallic green house. You'll see the castle on your left.
Keep left and keep on walking up the hill towards a pavilion, enjoying the incredible view along the way.
Keep on walking, sticking to the edge of the hill, always keeping left.
You will reach a park with playground, cross the small bridge.
Again, keep left and stick to the edge, walking till you reach a larger pavilion style building. (you will feel like you have lost your way because it's so quiet and untouristic, but you are on the right track).
Along the way, you may chance upon a small Julius Caesar monument by a small pond.
Walk along a large beautiful garden, passing an old terrace with domed window frames, as well as a metallic green house. You'll see the castle on your left.
Keep on walking until you reach a bridge on the left that leads to the castle.
Enter St Vitus Cathedral (there will be a queue, to avoid it, visit as early as possible)
Then explore the rest of the castle, and head down the crowded tracks towards Lesser City
On the way towards Charles Bridge, drop in St Nicholas' Cathedral.