Where is the first of these items?

Hint 1 of 5:

It is just out in the open.

Hint 2 of 5:

Look at the tree root on the Windswept Road.

Hint 3 of 5:

You'll need to force the horse out from its location.

Hint 4 of 5:

A spell will help you here.

Hint 5 of 5:

There's one in the mansion (just past the dog and fence).  See the "Other
Puzzles" section if you need more help.