Gihan J.
Google
Absolute must visit on the island of Aegina. Comparable to the Parthenon but with no crowds - my partner and I were the only ones there when it opened and it felt like a private tour. Views of Athens and surrounding coastline are amazing as well.
Note - need to update hours on Google, it only opens at 10am. And plan accordingly getting there, there is a bus that goes every hour from the port, or it's an 18 euro one way taxi ride