The Marco Zero, a small 'Km 0' marker in the middle of the broad waterside Praça Rio Branco, marks the place where the Portuguese founded Recife in 1537. It has given its name, unofficially, to the square and its immediate surrounds. From here it's possible to take a boat (R$2.50 each way, 7am to 5pm) across the channel to the sculpture park on the breakwater featuring works by Francisco Brennand.
The park is centered around the unusual 32-meter-high Coluna de Cristal the original design of which caused a major stir for being too phallic and was subsequently modified by the artist.