Alejandro de Humboldt National Park is generally considered the richest patch of nature in the whole Caribbean, and on a bike you approach it the hard way, through mining country and over some of the worst roads in Cuba. The park covers a huge block of mountains and rainforest in the far east of the island, between the nickel town of Moa and Baracoa, and runs down to the coast at Bahía de Taco, where a small visitor station organises guided walks and boat trips into the mangroves.
The secret is in the soil. Much of the park sits on serpentine and other ultramafic rocks, laden with metals and poor in nutrients, which is exactly why the same hills are mined for nickel around Moa. Plants that manage to grow on such ground have had to adapt, and isolation over a very long time has produced an astonishing number of species found nowhere else. Botanists still turn up new ones. UNESCO listed the park in 2001 and named it after the German naturalist who travelled through Cuba in 1800 and 1801 and wrote extensively about the island.
Animals are mostly small and shy. The almiquí, a strange, long-snouted insectivore called the Cuban solenodon, lives here; so do tiny frogs, colourful land snails and the Cuban parrot. The ivory-billed woodpecker was last reliably reported in these mountains in the 1980s, and naturalists still dream of a sighting. The guided trails lead to waterfalls and river pools that are as good as any reward after the ride in.
The ride in deserves its own warning. The coastal road between Moa and Baracoa is notorious, with stretches of rubble, deep potholes and sections washed out by the heavy rain that falls here throughout the year. Expect to stand on the pegs, expect trucks, and allow far more time than the map suggests. The red earth turns to grease when wet. Further inland, the area around Río Guayabal de Yateras offers another approach through coffee hills, no easier but with fine views.
Fuel is scarce and supply uncertain across Cuba, so fill up in Moa or Baracoa when you can and carry spare. Baracoa, the oldest Spanish settlement on the island, is the better base: a small, friendly town with cocoa and coconut in its cooking and El Yunque, a flat-topped mountain, standing guard behind it. Bring rain gear in any season and something warm for evenings in the hills.