Grandpa Gohan is a traditional cache which is part of the Dragonball series. You can treat this cache as an indiviual cache or as part of the series. If you plan to do more of this series (highly recommended) then I suggest look at all the others first and plan ahead and take notes or photos of everything on the inside of the lid of every cache.
Son-Gohan
is Goku's late Grandfather who has for one day been granted to walk in the land of the living. Fortunetelling Baba has given him this gift in exchange for being one of her figthers for that day.
For this cache Grandpa Gohan has been practising his fighting skills in a large under-used sports park. You must ascent a couple of hundred stairs to find him there and he'll give you part of the coords to find Fortunetelling Baba. See spoiler for help Somewhere here that used to belong in that picture, you will find the cache inches away.
Oh and this park contains one of the biggest concrete slides on the island. Slide down it, if you dare!