Grijalba-2 is one of the quiet corners of southern Costa Rica where a lost civilisation left its mark in stone. The site is part of the group called the Precolumbian Chiefdom Settlements with Stone Spheres of the Diquís, a UNESCO World Heritage listing from 2014 that covers four archaeological sites in the delta of the Térraba river, close to Ciudad Cortés. The spheres themselves are the puzzle. Carved from hard rock and ground to a startlingly smooth, nearly perfect roundness, the biggest are more than two metres across and weigh many tonnes.
Nobody knows exactly why they were made. The people of the Diquís chiefdoms, who lived here before the Spanish arrived, probably used them to mark status and to lay out the ground around their houses and mounds, and some were once arranged in careful lines and triangles that seem to have followed the sky. Most were moved, buried, broken or carried off for garden ornaments after the banana companies cleared the land in the twentieth century, which is how the world learned that they existed. Some at least are still where they were first put.
The ride down here is part of the point. The road from the Central Valley drops off the cold high pass into hot, wet farmland, and by the time you reach the delta the air is thick with the smell of wet earth, palms and cut grass. It is flat and straight, sometimes lined with oil palm and banana plantations, and the pace slows to match the heat. Expect afternoon storms, lorry traffic and the occasional pothole, and take a good rain jacket.
Ciudad Cortés is the nearest town, only a short distance away and small enough that fuel and a bite to eat are possible but not guaranteed to be convenient. If you are low, fill up at Buenos Aires, the larger town some thirty kilometres back, before you come this way. The sphere sites have their own rules and sometimes small fees, and the main museum is at a different site, so take a few minutes to check what is open before you settle on a plan.