For nature & scenery, Aegina Island Day-Trip delivers.
Aegina is the low-friction island fix: a fast ferry, sandy beaches, the lovely Temple of Aphaia and famous pistachios, all doable as a relaxed day. The catch: it's the least 'wow' of the Saronic islands and the port town is workaday — people chasing postcard Greece sometimes wish they'd pushed on to Hydra.