In the XIIth century Marin was declared as "Town of Crown" and since the XVIIth century it has gained great importance. Due to the low depth of the Lerez river, all the commercial activity moved from the port of Pontevedra to the port of Marin. Marin was one of Galicia's few ports authorised to trade with the American colonies, where a great number of people from Marin emigrated during the XVIth century and in the 1940s. Nowadays Marin is the third fishing port of Galicia and the base of the Naval Military Academy, founded in 1943.

The people of Marin fought bravely together with the English against the French in the Battle of Pontesampaio, and after the war they intensified their relations to a point where various Anglican pastors came to predict in Morrazo thus converting the parishes of Santa Maria do Porto and Seixo protestant.

In Mogor there is the most famous and symbolic carved stone of Galicia, near the tumulus of Mamoa do Rei and Chan de Arquina. Other historic monuments in Marin are the old Soaxe's bridge and the manor house and chapel of San Brais in Seixo, the Sete Espadas' church in Mogor, and Santa Maria do Porto's church in Marin.

Both Mogor and Aguete's beaches are visited during all the summer long by hundreds of tourists, and especially the nautical club and port of Aguete, the ideal place for water and nautical sports. Other natural spaces less frequented by tourists are the lsle of Tambo, the river Loira fishing reserve and the Coto-Redondo and Castinneiras lake.

From this point there is a nice view of Vilaboa, Moana, Soutomaior, Sanxenxo, Poio, the isle of Ons and O Grove. The most popular festivals in Marin are Santa Maria do Porto sea pilgrimage, the Seven Swords Festival at Mogor, the Hunters Festival in the Castineiras lake, San Blas in Seixo and San Miguel of Marin with its famous sword dance.