To do the Abraao trail (Trilha 1) is a stroll in the park
provably the easiest of all sixteen trails (trilhas) to choose from in Ilha Grande
Besides you can combine a nice swim at Praia Preta (Black Beach) with a visit to historic sights such as the Leprosarium and Aqueduct - the latter still in use at present time btw.
And if you feel energetic enough you could continue trekking for another hour or so to cachoiera (waterfall) of Feiticeira. I missed it that morning but reached Feiticeira beach by boat two days later.
Preta beach is a lovely spot about twenty minutes walk from Abraćo village ideal for swimming, snorkeling or just to have a relaxing day under the sun. It's partially covered by black monazite sand - and other minerals - considered to have medicinal properties.
Right next to it are the ruins of the old Lazareto (Leprosarium). It was the first one in the country, operative from 1886 to 1913. According to history it was a farmhouse (Fazenda do Holandes) bought by Pedro II - then Emperor of Brasil - to operate as quarantine stopover for boats coming from Europe to the New World.
It was seeing as a way to keeping at bay the spread of cholera epidemic and other contagious diseases brought by infected immigrants. Over four thousand boats were assisted during that period.
In 1940, under the tenure of President Getulio Vargas, the old Lazareto became a federal penal colony under the name of Colonia Penal Candido Mendes. It was operative until 1954.
Following the Abraao trail, the old Aqueduct (Aqueduto) comes to sight. It was built in 1893 to supply water to the Lazareto. With 125 meters of extension, it's one of the monuments of historic importance in Ilha Grande.
In case you are planning a visit to the island find out how to get there and where to stay.