The Neptunalia was the two-day festival of in honor of the god Neptune on July 23, about a month into the hot, dry summer. The date and the construction of tree-branch shelters reveal there was a primitive role for the god Neptune as god of water sources.
Neptune is in Pisces right now, the sign it rules, and this is a powerful time for all things involving water — the oceans, rivers, seas, lakes and streams. It is also good for spiritual exploration, paying attention to your dreams, envisioning your immediate future, flowing instead of fighting, and being creative in your approaches to problems and in general.
During this time committees of citizens could have the unusual privilege of voting on civil or criminal matters. People constructed huts of branches and foliage and then drank spring water and wine to keep cool, feasted and amused themselves with games and other pleasures. Men and women could converse and enjoy each others company without the usual Roman traditional social constraints. A bull, representing agricultural fertility was sacrificed.
This festival actually fell in the midst of two other festivals: From July 19-21 the two-pronged Lucaria festival was devoted to dressing the woods and clearing the undergrown bushes (July 19) on the surface and later to uprooting and burning foliage (July 21). Then on July 23, during the Neptunalia, the foliage remaining was used to build the sheltering booths. Finally, on July 25, there was a Furrinalia celebration focused on the goddess Furrina who governed wells and springs (water captured by drilling into the earth).
Laying around under an umbrella shelter of leaves, drinking spring water and wine, feasting on good food, chatting with other people, doing special things. Somehow, I can see Neptune riding his sea horses across the Pacific Ocean like a master surfer and cooly coming in for some something to eat. Yo, Neptune dude!
Sounds like a good summer party, eh?