South of Curitiba the Serra do Mar stops being a distant wall and becomes a country of its own, folded into sharp green peaks that rise from the coastal plain of Paraná to well over a thousand metres. The Serras do Cordeiro belong to that mountain tangle, in the zone of protected land and state parks around Pau Oco, near the town of Quatro Barras. Pico Paraná, the highest summit in southern Brazil, and the pyramid of Marumbi are the big names nearby, and the whole range is blanketed by Atlantic forest, a wet, mossy, orchid-hung woodland that catches the clouds coming off the ocean and drips for most of the year.
What strikes a visitor is how abrupt the change is. Within an hour of Curitiba's tidy boulevards you can be in cold fog under tree ferns, with bromeliads on every branch and the sound of water from hidden streams. Howler monkeys, toucans and a great many frogs live here, though the forest is thick enough that you will mostly hear rather than see them. The mountains were also a barrier that made the Paraná coast remote for centuries, and the old roads across them are a story of their own. The Estrada da Graciosa, which links Curitiba with the sea at Antonina, was opened in the nineteenth century, and its cobbled sections and forest hairpins are still among the most beautiful drives in the state.
For a rider this is serious fun. The BR-116 and BR-277 descend from the plateau in long, busy grades with lorries and fog banks, while the Graciosa and the smaller roads wind more gently, with potholes and wet leaves to watch for. Weather is the main variable, because the mountains can swallow the sun in minutes and the temperature falls fast. Winter, from June to August, is cool and sometimes frosty on the plateau, while summer brings warm downpours. Clear days are best in autumn, when the air is crisp.
Quatro Barras, sixteen kilometres away, is a town of about seventeen thousand people and the sensible place for fuel, bread and coffee, and Curitiba has everything else. On the coastal side Morretes serves barreado, a slow-cooked beef stew eaten with manioc flour, which is the classic reward after the descent. Several trails are managed by the state parks authority and require booking or registration, so ask ahead. Carry a rain jacket and a warm layer, and do not leave the marked path, because the forest closes behind you quickly.