Each town in Galicia has it's own specific historical costumes, food and smaller festivals, making Entroido a celebration of each town's unique history and culture.
Carnaval has ancient roots in celebrations that honored the Roman god of wine, Bucchus. When Catholocism became the dominant religion in Spain, the pre-existing Carnaval was refashioned to resemble other celebrations of excess, such as Fat Tuesday in New Orleans, before the official beginning of Lent. During the dictatorship of Franco in Spain, all Carnavales were forbidden because their use of satire, humor and dance were seen as possible threats to the strict hold of the dictator. However, towns in Galicia continued celebrating their Carnavales; not only resisting oppression, but preserving their cultural heritages in the process.
I attended the entroido of Xinxo de Lima, a small town in the province of Ourense, about an hour and a half from where I live. Xinxo de Lima is known for having the longest Carnaval celebration in the whole of Spain -- they start celebrating five Sundays before the official start of Lent!
Entroido is definitely connected to the environment! Some scholars have pointed out that because of the Celtic roots of Galicia, Carnaval's historic roots here might be more tied to Celtic (pre-Roman) agriculture and livestock purification rites.
