Waves of Dark History Break on an Olympic Pool

In a few weeks, as TV cameras swoop over the Olympic Park in the Barra da Tijuca neighborhood of Rio de Janeiro, viewers will glimpse what looks like a colossal seascape mural encircling the new aquatics stadium.

But what appears to be ancient, cracked decorative tile is actually a scrim of 66 panels of perforated canvas, each 90 feet high — the largest contemporary artwork commissioned for Rio 2016. And the blue-and-white work is steeped in a complicated past that is typical of its creator, Adriana Varejão, 51, the revered Rio artist.