This city in northern Portugal got a light rail system in 2002. At street level, tracks are often embedded in grass. 15 of the 78 stations are underground [mporto.no.sapo.pt].
Photo [Nuno Fonseca, fotopic.net]: Entrance of Pólo Universitário station (2004).
Underground station architecture, surface-station furniture, signage and typography are quite consistent in their cool minimalistic elegance. Predominant materials are concrete, glass, and steel. Architect of all stations is Eduardo Souto de Moura, a former student of Alvaro Siza.