A small, protected lake basin, this is a peat bog in the slow process of silting up, surrounded by a dense forest of beech and alder trees. Its name comes from the wood sorrel (Oxalis acetosella) that grows along the banks, whose leaves resemble clover. The site is of considerable scientific interest for its unique flora and fauna; it hosts the rare royal fern (Osmunda regalis), with fronds that can reach 180cm, as well as a notable population of amphibians, including the alpine newt and the spectacled salamander. A picnic area with tables is set up near the shore, and a short path connects to the nearby Fontana Trifoglietti, a freshwater spring. Bathing is not possible. From the Strada Statale delle Terme (SS283), take the exit for Fagnano Castello. Follow the signs for the 'Laghi di Fagnano', heading uphill into the mountains. The road leads directly into the Parco Naturale del Monte Caloria. Lago Trifoglietti is the first of the lakes you will encounter, located on the right side of the road. Parking is available in small clearings by the roadside. From the nearby Fontana Trifoglietti, a marked trail of about 2.7km begins, leading towards Lago Frassino. Sources: Calabriaportal.com; Gal Valle del Crati.