Huanzala has been praised as one of the great pyrite localities of all time,
primarily for the number of spectacular specimens in museums and great collections
around the world.
Contributing to its greatness is also the amazing variety of pyrite crystal forms and habits unmatched by any others.
Perhaps that sounds like an uninformed claim, but it's made by someone with a D. Min.
(Unfortunately that stands for Doctor of Ministry not Mineralogy, and I'm simply a hobbyist who gets carried away when I see another affordable, wonderful piece of pyrite.)