Description
Korpinkierros (Raven Trail) is about 6.5 km on authoritative GPX through Nuuksio National Park west of Helsinki, in Uusimaa. Vihti lies among the municipalities around the park, and the circuit threads lake shores and rocky forest between Haukkalampi and Siikaniemi. Metsähallitus lists this as one of the park’s main marked day hikes; for closures, rules, and the official route description, use the Korpinkierros trail page on Luontoon.fi. Natura Viva, which runs the Haukanpesä visitor point at Haukkalampi, describes the trail as a challenging yellow-diamond hike with picnic and camping infrastructure along Mustalampi and Holma-Saarijärvi, and notes seasonal café and rental services at Haukanpesä. Retkipaikka’s Luontopolkumies walk-through gives a practical feel for pacing, surfaces, and how the loop splits from other colour-coded routes near Mustalampi. One Man, One Map’s English report adds detail on Kolmoislammet, the Rajakallo rock section toward Mustalampi, and the busy but scenic shores at Haukkalampi.
From Haukkalampi you pass two parking areas—Haukkalampi iso pysäköintialue and Haukkalammen pieni pysäköintialue—before the path reaches the Haukanholman telttailualue and the Mustalampi shore. Around Mustalampi there are several cooking shelters and campfire rings (Mustalammen keittokatos, Mustalammen pieni keittokatos, Mustalampi tulipaikka2, Mustalammen tulentekopaikka) and tent pitches on both sides of the lake. Closer to Haukkalampi visitor activity, Haukkalampi Haukanpesä varaussauna and Haukanpesän laituri sit by the water; Haukkalammen laituri is another small dock along the shore. Mid-loop, Kolmoislampi varaustulentekopaikka, Kolmoislampi varattava telttailualue, and Kolmoislammenranta varaustulentekopaikka offer reservable fire and tent spots, with Kolmoislammenranta kuivakäymälä nearby. Nuuksion Hparkkipaikka - etelään gives an alternative access with parking south of the Kolmoislammet area. Toward Holma-Saarijärvi, Holma-Saarijärven länsipuolen tulentekopaikka, Holma-Saarijärven itäinen tulentekopaikka, Holma-Saarijärven länsipuolen telttailualue, Holma-Saarijärven itäinen telttailualue, Holma-Saarijärven laavu, and Holma-Saarijärven itäinen käymälä cluster at one of the prettiest lake sections. The loop returns toward Haukanholma with Haukanholman keittokatos, Haukanholman tulentekopaikka, Haukanholman laituri, and again Haukanholman telttailualue. Dry toilets sit near several shelters; use them rather than naming each structure in running text.
The route meets Reitti 2000 near the Haukkalampi end, shares places with Solvalla–Haukkalampi connecting trail, and links via Siikaniemi to Korpinkierros connector trail and Siikajärvi–Korpinkierros connector trail to other Nuuksio day routes; Holma-Saarijärvi laavu spur branches toward laavu-focused walking at Holma-Saarijärvi. Expect company on fine weekends—start early or consider Siikaniemi if Haukkalampi parking is full.