Meet Grandma at Pilgrim's Peak: Meet Grandma at the chapel of Pilgrim's Peak.
The quest "Meet Grandma at Pilgrim's Peak" is started after the cutscene with Grandma in Turtle Rock campsite. The player is required to have completed the "Fix the cable car" quest in order to reach this point.
Mama Mia thatsa lotta steps. This is a rough draft.
In order to complete this quest, the player must first repair the rope bridge, using the rope that can be found on the ground next to where Grandma is sitting in Turtle Rock campsite. After repairing the bridge, head West across it towards Mr. Berd's house. If the player continues along the obvious path up the hill and across the bridge heading East, they will find that there is another broken bridge. This bridge does not have it's own dedicated quest but does count as a repairable item for the "Maintain the Park" quest. However, as Flint notes, this bridge needs to be repaired from the other side.
Head back West, past Mr. Berd's House, and along the hidden path leading North, along the cliff. On this path are two repairable fences, as well as one of the 5 Snow Flowers at it's Northern most point. Follow the path East, underneath a drawbridge with a rabbit standing guard. Another of the 5 Snow Flowers is just East of this point, at the edge of the cliff.
Take this opportunity to repair the broken bridge to the South. Then, follow the path leading up the hill towards the rabbit. After speaking to the rabbit, the player will learn that he is Robin the 15th, who has a quest for the player: "Bring back the crown to Robin". The player will need to complete this quest, along with "Find a Royal Nose for the Snowman", before being able to continue. Guides for both quests can be found on their respective pages.
After completing the quests mention above, the player will have gained access to the Old Castle campsite. Just North of the campsite is an old canon that can be lit and climbed into. Doing so will launch the player across the valley, onto the other mountain, in the Pilgrim's Peak region of the map. The player must then make their way Northwest, towards Lighthouse Bay, until they find a path leading up the hill and East, towards Pilgrim's Peak camp. Continue following the path until Pilgrim's Peak campsite is discovered. On the Southeast corner of the camp is a path with a direction sign, which will lead the player to the Chapel of the Pilgrim. There, the player will find Grandma, who is sitting on a bench. Walking towards her will trigger the completion of the quest, as well as begin the final cutscene.
After completing "Meet Grandma at Pilgrim's Peak", the Hot Air Balloon will be unlocked, a vehicle which allows the player to fly all over Haven Park.