We don't need the caffeine on offer at Don Pedro's; adrenaline is already running high, like the Penas Blancas river itself, swollen after days of rain and littered with broken branches some of which bear an uncanny resemblance to mud-caked crocodiles. Our guide, the aptly-named Crazy Luis, delights in spinning our four-man inflatable raft round and round in the cappuccino frothed waters faster than waltzers at a fairground.
Luis' other, more valuable, trick is mimicry. Without warning he tilts back his head and utters a series of harsh, guttural grunts and squeals. Almost immediately, the forests on both banks ring with a similar cacophony. And then we see them, Costa Rica's famous howler monkeys, loping gracefully though the tree tops. All but one is black, but we are privileged to see 'Blondie' a rare albino female, sitting apart from the others, as if aware of her special status.
We float onwards, the hundred shades of green on either side vividly streaked here and there with scarlet or yellow flowers spilling into the shallows. Luis asks 'You thirsty? I take you to my friend's house for nice cup of coffee.' Looking around us, all we can see is impenetrable forest; we smile indulgently at his joke.
A little further on, though, Luis slews the raft suddenly to the shore and we disembark at a small clearing. Clambering up the muddy bank we are aware of a wooden shack, the front elevation entirely open to the elements. As we get nearer, we see an old man, stick-thin, his eyes cloudy with cataracts, arms extended in welcome. 'My friend, Don Pedro. He's ninety-two years old,' says Luis. We shake hands in turn. 'English?' he asks me.
'Ah, Clement Attlee! Very good man.' He nods vigorously and chuckles. Eager to prolong the exchange I toss another name into the air, 'Winston Churchill?'
'Pah, Winston Churchill,' he echoes, this time with a spit and scowl.
Our game of prime-ministerial ping-pong is interrupted by a woman, (Don Pedro's wife? daughter?) who ushers us to the table. One end is set with lace doilies, china cups and a vase of plastic roses, the other houses a tin bath filled with onions, several plaster statues and a 1978 calendar of the Swiss Alps.
We are served crispy cassava chips and sticky-sweet fried plantains with our coffee. Luis and the Senora have wandered outside to the small vegetable garden and hen-run; Don Pedro appears to have dozed off in his rocking chair. We sit in contemplative silence, gazing around the room, which houses a bed and rudimentary kitchen. Outside is an ancient, but functioning flush toilet. There is no discernible path, let alone road, within sight.
The other two return. Inspired by the chickens, Crazy Luis squawks and flaps his way back to the moored raft; it's time to make our farewells. Don Pedro is smiling once more as he pats my hand. 'Ah, England. Bye bye.'