Can I get into the castle?

Hint 1 of 5:

You can't go straight in the front door.

Hint 2 of 5:

Go around to the side of the castle.

Hint 3 of 5:

That grate looks interesting.

Hint 4 of 5:

Did you bring the crowbar from the sea shore?

Hint 5 of 5:

Apply the crowbar cursor to the grate.