Nope, we didn’t know it existed either.

Often prefixed with ‘Amazon’, rainforest is not a word we’ve ever associated with Scotland – but it turns out the west coast boasts a type of rainforest even more endangered than its tropical cousin.

Defined by National Geographic simply as “an area of tall, mostly evergreen trees, and a high amount of rainfall,” rainforests are found on every continent barring Antarctica, from the impenetrable jungles of the Congo to the temperate woodland on Australia’s northern coast.

If that sounds like a very loose definition, it isn’t, and according to the Woodland Trust the climatic conditions for rainforests appear on less than one per cent of Earth’s land mass. Britain and Ireland actually punch above their weight historically, once coated in a layer of ‘Atlantic’ or ‘Celtic’ rainforest.

Today only fragments remain, mostly on steep-sided hills and ravines that animals are unable to graze. Scotland’s ancient forests, mostly oak woods and hazel woods, now total a mere 30,000 hectares (a little over the area of Edinburgh), clustered mostly around the lochs of Argyll, Inverness-shire, and the Isle of Skye.

A lush labyrinth of twisted trunks and vivid greens, the forests boast biodiversity of international importance. They probably won’t end up on David Attenborough, but the mosses, lichens and liverworts rank among the world’s rarest, sprawling over boulders, trees and the forest floor.

Once described “a lichenologist’s Mecca”, by the Scotland’s Scientific Advisory Committee, a single ravine near Knapdale houses up to 200 varieties of these so-called ‘lower plants’, around a quarter of the UK’s native species.

Now, the Alliance for Scotland’s Rainforest (a voluntary partnership of 20 conservation organisations), is launching an urgent appeal for funds to protect the forests from a litany of threats. Grazing by sure-footed deer, nitrogen pollution, climate change, diseased ash trees, and strangulation by invasive rhododendrons all threaten this most historic of habitats.

Campaigners need roughly £850,000 to save two crucial projects – one in Argyll, the other in the Highlands – and compiled a video seeking support.

When staycation season returns, the Alliance has picked out 25 of the finest forests for visitors to enjoy, spanning the sturdy oaks of RSPB Glenborrodale to the Caledonian pinewoods scattered across the islands of Loch Maree.