It's a sequel to LttP, Masters, and is actually called The Legend of Zelda: A Link to the Past 2 in Japan. The Hyrule overworld is really quite similar, but there are enough differences to make for some very interesting play (and then the world of Lorule REALLY adds new wrinkles). As someone who spent a lot of time with LttP, I was surprised that the experience in some ways ADDS to the new one, rather than making it feel like a retread. My two favorite Zelda games are still the original two, for the NES. And number three is now this one, as noted. :-D
"Too often we enjoy the comfort of opinion without the discomfort of thought." - John F. Kennedy on reality
"What if everything you see is more than what you see--the person next to you is a warrior and the space that appears empty is a secret door to another world? What if something appears that shouldn't? You either dismiss it, or you accept that there is much more to the world than you think. Perhaps it really is a doorway, and if you choose to go inside, you'll find many unexpected things." - Shigeru Miyamoto on secret doors to another world