Porto’s metro is comprised of six lines (linhas), designated by letters (A through F) and colours. When entering the metro, you won’t pass through a physical gate. There will be a line of scanners mounted on posts. Place your ticket on a scanner to validate it. If you’re caught without a validated ticket, you’ll have to pay a fine.
Trindade Station is the central hub where all six lines intersect. Lines A (Blue), B (Red) and E (violet) leaving Estádio do Dragão with destination to Matosinhos (A), Póvoa de Varzim (B) or if you’re heading out to the airport (or coming in), take Line E. Line C (Green) connects Campanhã to Maia. Line D (Yellow), originates at João II in the south, running toward Hospital São João in the north. Line F (orange) connects the Senhora da Hora to Fânzeres.
The metro also functions as a light rail once the cars leave the underground tunnels. You can ride the tube from 06:00 to 01:00.