Quatro Fábricas de Luz is a linear route of only 2.1 kilometres, yet it crosses a decisive chapter in Azorean energy history. Ribeira da Praia provided the water needed for successive hydroelectric plants, and the trail makes their development readable on the ground. Reservoirs, conduits, buildings and ruins show how the same slope was adapted to different generations of technology.
From Parque Escutista dos Lagos, the route approaches the Fábrica da Cidade reservoir, now associated with a small plant that remains in operation. Farther down are the ruins of the Cidade and Vila stations, interspersed with woodland, waterfalls and sections where the stream again becomes the strongest feature. Cascata do Segredo and Poço dos Trinta Reis add natural landmarks to a corridor often remembered principally for its industrial structures.
On the descent towards Lugar da Praia, an old pipeline accompanies part of the path and leads towards the site connected with Fábrica da Praia. Entry to the museum requires separate confirmation and booking, but the outdoor route already explains the relationship between water, relief and electrification. Rated easy and taking around ninety minutes, this walk combines industrial archaeology with a wooded valley, finishing at a different elevation and requiring a transport plan.