Undeveloped hippie beach town island. Raw nature with many beautiful beaches and other islands nearby.
The magic being the “undeveloped” part. Unlike nearby Ilhabela island which has fully-developed roads and cars, far more crowded…Ilha Grande has a jungle beach bum oasis vibe. Dirt roads, far less people, actually see locals walking around barefoot. And while it’s casual and bum-ey, you also wouldn’t be so out of place if you want to dress up a little and go to a nice restaurant. It’s a perfect all-purpose island. All ranges of people, ages, etc, will enjoy Ilha Grande.
Beaches have many varieties, as typical in Brazil. Big space, little space, fish in water, rocks for beauty and elevated views, trees for shade, can walk to nearby ones, or hike/ferry to far beautiful ones. Plenty food options, from traditional to fancy. Only thing Ilha Grande doesn’t have is the “posh” vibe, and I like it that way! Non-pretentious, chill, beautiful, real.
5-7 days is a good start considering the effort to get here, 3-4 days can be minimum (but you’ll cry when you leave). Do I see it being a place you could stay for months and months? Probably not because of how far the better beaches are from town. A true beach lover would prefer nicer beaches within 15mins walk. But indeed, it has many things and a nice vibe.