White Oak, they built ships from it.
Three of the most popular lumber choices for outdoor furniture include cypress, western red cedar, and redwood. Hardwoods such as ipe and teak are also rot-resistant and durable. Other options include acacia, black locust, cedar, and cypress.
Ipe is dark in color and used for expensive decks and flooring. Kind of chocolate brown.
The best protection is exterior paint and spar varnish. If you finish the wood, you will need to refinish it occasionally.