Bassae, ancient Greek city on the Neda River in southwestern Arcadia. The city is now chiefly known as the site of the Temple of Apollo Epikourios (Epicurius; “the Helper”), built c. 450–425 bce. Pausanias, a Greek geographer of the 2nd century ce, considered the temple one of the finest in the Peloponnese. It is also one of the best-preserved temples in Greece, and it was inscribed as a World Heritage site in 1986.