Concierge.com's insider take:
Fly fishermen (and women) from all over the world come to the South Island for its whopping rainbow and brown trout. They know that not only are trophy-sized catches (weighing more than ten pounds) frequently made here, but the vast number of streams, rivers, and lakes on the island mean they'll likely have their favorite spot all to themselves. The concentration of rivers and streams around Nelson (there are more than 25) make the surrounding area a fly fisherman's dream. Day trips from Nelson can be arranged through Strike Adventure (64-3541-0020; www.strikeadventure.com); fishing in more far-flung areas requires staying at a lodge. The season varies by location but is roughly October to May, with the best months from November to April.