Koroni is a sleepy, pretty place that is in contrast to its sister town of bussling Methoni. It has steep backstreets with steps leading up to the castle and a harbour lined with restaurants and bars. We first visited Koroni on our honeymoon but decided to return in 2018 when we stayed the night in order to soak up the atmosphere.
Marjory McGinn recommended Parthenon restaurant to us and we had veritable fishy feast. We stayed at the pleasant Hotel Diana which had the smallest bathroom I have ever seen! It was like being in a cupboard! But the room was otherwise comfortable, the staff were very friendly and breakfast was yummy.
The 13th Century castle has some impressive structures and passages as well as amazing views. People still live within the walls and there is a working convent [20th century] and the ruins of an 8th Century church within the crumbling walls.
The Turks added features to the castle in the 16th century and the Germans occupied the castle during WW2 and used it to store ammmunition, they did not add anythng to the castle though, the opposite actually.