In comparison to Spain the manhole covers of Portugal are generally a meagre bunch. In many cases the covers feature only the initials CM (for Camara Municipal) followed by the initial letter of the place. This is true even for Lisbon. The name of the foundry is sometimes given. Pont-à-Musson has made some inroads here but more intersting are the names of early foreign foundries to be found in towns such as Porto.
Braga
Saneamento, C.M.B. Fundição Pachancho, Braga
Saneamento, A Mecanica, Braga, CM
Aguas de Cascais, Rexel, Esgotos.
CML, Esgotos, Fundição Crato
CM Mafra, Pluvias, 2008Perhaps the most interesting town in Portugal, the early manholes from Engand and Scotland reveal the port's long-standing trading links. The Polish manhole cover seen in the suburb of Gaia across the river is less easy to account for, perhaps a wrong delivery by the foundry at Pont-à-Mousson
C.M.P., 3a Repartição-Arruamentos
Fundicao de Masserellos, Porto. Seen in Braga
Glenfield Ltd, Paris et Kilmarnock
Hughes & Lancaster, London
Aguas de Gaia EM, Rexel, Saneamento, PAM. 
Wodkan Zgierz, Korum, PAM
CM Porto, Fundicao Aboinha, Aguas Pluvias
Fausto, CMC, Porto. Seen in Caminha
CIF, Porto. Seen in Valenca
SMAS Sintra, Aguas, Fucoli
F Tomarense, Tomar, SMAS Tomar, Esgotos