I'm looking for this story I've read a long while ago(around 2004-2005) and though I've searched for it on and off in the last years, i never managed to find it. Any help would be appreciated.

Title:Harry Potter and? Arcadia?(a name my mind probably came up with that in some way relates to the rest of the tittle that I don't remember, not really sure if it was a crossover or not since at that time there wasn't a crossover section)

Other things about it: English written, not sure about the rating, powerful harry, pairings harry&? (I don't remember if there was a pairing or not), not sure about what genre it was and it was one hell of a long story it had more than 90 chapters and more than 500k words I think even higher

Summary: Somewhere between his birth and a little after Voldemort attack(not 100% sure this happened) on the Potters Harry gets whisked/dragged/lands/is taken to another world?/subdimension of earth? Where time goes differently,10 years in Harry's new world amount to only one in canon .

The story details quite a lot of Harry's years in this new worldwhich is in a way a more buffed up magical world, more dangerous ,with stronger enemies and stronger allies as well as powerful magical artifacts ,a more cunning than canon Harry who could wipe the floor with Dumbledore and Voldemort at the same time. Of course old Voldy has a counterpart in this world that's hell bent on power,rulling the world,yadda yadda the usual stuff vilains do with the exception this one is like Voldemort on evil steroids and more monster like than voldy will ever be.(think somewhere along the lines of let's an imprisoned old god, best example I could give is yogg saron from world of warcraft game)

Harry has his usual share of adventures and mysteries to solve in the 110 years he lives here, sometimes butting heads with the supreme evil guy , until he somehow lands back in canon universe for his first year at Hogwarts being about the same age as Dumbledore mentally with a Voldy making contact with the bad guy and getting more powerful. I think the philosopher stone scenario plays again but this time Harry is not a little boy not knowing much and Snakeface gets his ass kicked in the end and Harry takes a vacation from Dumbly manipulations on the other world only to come back for his 2nd year where my memory kinda stops about anything related to this story.