Though there is a building boom going on in Aegina lately, it is surprising that a pretty island so close to Athens (1 ¼ hours by slow ferry, and 35 minutes by hydrofoil) wasn't totally ruined by tourism twenty years ago.
As it is, the lovely neoclassical harbor town (also called Aegina) does get very crowded with both Athenians and non Greek tourists.
And there are so many who commute either daily or at greater intervals from Athens that some have called it a bedroom community or suburb of Athens.
At the same time, there are still plenty of fisherman, who supply the wonderful fish market, many vegetable sellers, bakers, and local businesses of all sorts, run by people who live and work on the island full time, and some very lovely countryside that feels far from the busyness of the huge metropolis across the water.
Main sites, all located in the same heavily wooded hills in the northeast part of the island, include the large, recently built church of Greece's most recently canonized saint, Aghios Nektarios, the abandoned 9th century AD island capital of Palaiohora, said to have had 365 churches, (though only a few are more than ruins), and the 17th century convent of Khryssoliondissa, high on the mountain.
Perhaps most outstanding,however, is the Temple of Aphaia, dating from the 5th century BC, high on another pine covered hill towards the east coast, one of the best preserved ancient temples in Greece , with many of its columns still intact. The most traditional village on the island is in the same vicinity, where some of the locals make their own retsina, tapping some of the local pine trees resin.
Beyond it on the east coast is the main tourist resort of Aghia Marina, very much a package resort, and without clean water for all that its beach gets quite crowded. There's a ferry link to Piraeus here. The west coast resort of Perdhika is lower key, and a picturesque place set on a small bay at the end of the coast road 9 km from Aegina. Outside of the main town, it offers the most choices for non-packaged accommodation.
Across from Perdhika is Moni Islet (Monastery Islet), where there's an official EOT ( national Greek tourist organization) campsite. Though there's a preserve on the island for the wild (and endangered) Cretan mountain goat , there's also a small beach with trees and peacocks strolling around. The ferry over to it takes only ten minutes. Pistachio orchards dots the island, which is the pistachio capital of Greece, and the island in general has a sunny, fertile look to it, except for the rocky Mt. Oros in the south, the island's peak, at 532 meters. There's a chapel on top with great views of the island and much of the Saronic Gulf. Aegina is the home of the amazing Hellenic Wildlife Hospital in the vicinity of Mt. Oros, where sick and injured animals (mostly birds, though some mammals as well ) are brought or sent from afar, for rehabilitation and release, if feasible, back into the wild. Volunteers work there with the regular staff and visitors are welcome. As thousands of birds, many of them birds of prey, are injured by hunters annually, this hospital is one of the keystones of wildlife preservation in Greece. There is some fine walking paths on Aegina, with a very good books for sale in the local stores, written by a resident Englishman who leads walks on Sundays. Ask around for Gerald.