A short walk north of the centre, the Parque El Arenal is a green oval around a small artificial lagoon, popular with joggers in the early morning and with couples in the evening. The lagoon is fringed by trees and broken up by a small island in the middle, on which sits a long curving wall carved with a relief mural by the cruceño artist Lorgio Vaca — a stylised history of the region from pre-Columbian times through to the founding of Santa Cruz.
You can hire a paddleboat for next to nothing, walk a lap of the lagoon in fifteen minutes, or just sit on a bench under the trees with a tereré. It is not a sight in its own right, but it is a pleasant break from the hot streets of the centre.