People surf on the wave of a tidal bore known as "Pororoca" at Mearim River in Arari, Maranhao state, Brazil, on April 22, 2023. - Pororoca, an admired and feared river wave by surfers in Brazil Amazon, is created during the spring tide when the Atlantic Ocean currents push back the Mearim River's water. (Photo by NELSON ALMEIDA / AFP)