"Prowling the Grounds" was the main hub for Tide of Terror in Sly Cooper and the Thievius Raccoonus. Since no missions take place in this hub world, there isn't a walkthrough. Rather, this will be a simple explanation of the world.
To get access to Raleigh's storm machine, you must unlock a cannon, that way you can launch your way up there. After collecting all seven treasure keys, the cannon can be unlocked, allowing access to the final level "The Eye of the Storm."