Do I need a guide to do the Levadas (e.g., 25 Fontes, Alecrim, Ribeira da Janela)?

The recommended trails (PRs) are well-marked and safe to do independently, provided you respect the official warnings, wear appropriate footwear (hiking boots), and bring a flashlight (for the tunnels) and water. If you prefer an explanation about the local fauna and flora, hiring a guide is a great addition to the experience.