There are four versions of this farm:

Hill-Top: Standard version, Adds a new area to the bottom of the Hill-Top farm. Changes wooden bridges to Stone Bridges (like town). Widens the stairway to grandpa's shrine. This version of the farm is less compatible with existing farms than the compatible version (NEW FARMS ONLY RECOMMENDED)

Alternate Hill-Top: Alternate version, Adds a new area to the bottom of the Hill-Top farm. Changes wooden bridges to Stone Bridges (like town). Widens the stairway to grandpa's shrine. Removes raised area below the farm house as well as the patch of grass below the quarry. This version of the farm is less compatible with existing farms than the compatible version (NEW FARMS ONLY RECOMMENDED)

Compatible Hill-Top: Standard version, Adds a new area to the bottom of the Hill-Top farm. Changes wooden bridges to Stone Bridges (like town). Widens the stairway to grandpa's shrine. This version of the farm should be used for existing farms (BEFORE USING, CLEAR ALL 6 TILES LEADING TO THE FOREST)

Compatible Alternate Hill-Top: Alternate version, Adds a new area to the bottom of the Hill-Top farm. Changes wooden bridges to Stone Bridges (like town). Widens the stairway to grandpa's shrine. Removes raised area below the farm house as well as the patch of grass below the quarry. This version of the farm should be used for existing farms (BEFORE USING, CLEAR ALL 6 TILES LEADING TO THE FOREST)

The main difference between whether or not I deem the farm "compatible" is if the cliff with the gap leading to the new area is straight all the way along the top or not. For aesthetic reasons I personally prefer it to not be a straight edges (nature isn't perfect), but for those who would prefer it this way, you may even want to choose a "compatible" farm for your new characters.

PLEASE READ: For users of the "Compatible Alternate Hill-Top" version, you will notice the bushes that were on the raised area below the farm house are still there. These cannot be removed by replacing files, they are created at the start of the game. FEAR NOT, they can be removed, simply use Stardew Valley Save Editor (available here on nexus) and edit your save to remove them. It is simple and safe.

Instructions:
Extract my files.
Navigate to Steam\SteamApps\common\Stardew Valley\Content\Maps.
Back up "Farm_Mining.xnb" and "Forest.xnb".
Override with my files.

The reason you need to override Forest.xnb as well is to alter the warp co-ordinates from when you travel to and from the forest and farm.

CHANGELOG:

1.2: Widened stairs leading to grandpa's shrine.
       Fixed an issue with spouse areas loading the incorrect tiles.
       Various minor tile inconsistencies fixed. 

1.1: Reverted grass in "spouse area" back to cobbled grass.
       Changed grass tiles visible under greenhouse to shadowed dirt tiles.
       Alternate farm also removes indestructible bushes from where the raised area was (new saves only).

Thanks for downloading, I welcome suggestions and bug reports (though when it comes to suggestions try to keep them small, and ill probably only do them if I feel it's an improvement that can be made and not just another alternate version).