Contributing Travel Editor, green girl and SPA.Kitchen founder, Daisy Finder, rounds up the world's best ethical holidays. Have you tried treehouse living?

Restorative hideaway: Pedras Salgadas, Portugal

Staying in a woodland eco-treehouse in the Pedras Salgadas Park, 90 minutes from Oporto in rural northern Portugal, guarantees a restorative, back-to-nature experience. You wake up to birdsong, and at the end of outdoorsy days spent hiking, biking, or exploring the treetop adventure course, can retreat into the magnificent 19th-century Pedras Salgadas spa at the heart of the park for a wonderful massage, peaceful swim or restorative Turkish bath.

Built in 1879 following the discovery of hot springs in the area, royalty visited, and for decades it flourished. An impeccable restoration job in 2009 returned the spa to its former splendour, and since the unveiling in 2012 of seven woodland eco-houses and three treehouses, Pedras Salgadas has become the site of some of the best-value, four-star healthy holidays around.

A few minutes’ walk along a woodland path from the spa building, Casa de Chá restaurant and lounge, and outdoor pool and playground, the eco-houses are slightly larger, with a bedroom, sofa-bed in the lounge, kitchenette, shower room and shady deck. But the slate-and-wood treehouses beat them for romance. Approached via long walkways, they are more secluded and it feels thrilling to lie in bed, looking up at the stars, listening to the wind rustling the leaves. You almost pray for the extra cosiness of rain. AP

A two-night break in a treehouse for two with breakfast, a lunch and spa treatment costs from £520. Visit pedrassalgadaspark.com, +351 259 437 140