The walk starts at the entrance to the hamlet of Merrien, on the road coming from the village of Moëlan-sur-Mer. You can park here or drive on towards Kercarn (a dead-end street). However, these aren’t really designated parking spaces, so you’ll need to find a spot where you’re least likely to cause a hindrance. You can continue 300 m towards the centre of the hamlet, where there is a proper car park, and walk back to the starting point.
(S/E) Take a wide track heading north-east. Please note: the turn to the right is not where it is shown on most IGN maps, but a little further on, in the fields.
(1) Once you’ve entered the woods, you’ll soon come to a lovely path marked in yellow (the path can be very muddy, or even flooded, where it crosses the stream after heavy rain) and arrive at the small hamlet of Saint-Thamec.
(2) On leaving the hamlet, take a small, very wild path that descends to Anse de Portec (there are several possible routes through the hamlet; I’ve marked my favourite one on the map).
(3) Turn right and take the coastal path westwards (GR®34andGRP®) to Anse de Porz Bali
(4) Turn north onto another very wild path that climbs back up towards Kercarn (S/E).