ilha guaraquessaba is located in sepetiba, in the saco do piai, a small basin between sepetiba and pedra de guaratiba.

the largest of the three islands situated half a kilometer of fthe shore of the 'área de proteção ambiental das brisas', or (brisas environmental protection area), guaraquessaba is a very small island, amounting to little more than a rock rising from the waters of the sepetiba bay.

even smaller, is its sister islet, located on guaraquessaba's left.