Kastania (Greek: Καστάνια) is a village in Mesa Mani of Laconia, Greece.

[2] Kastania is 28 km northwestern of Gytheio at the southeastern slopes of mount Taygetos.

A short distance below the village is the early Christian chapel of Ayios Stratiyas.

Overlooking the village from its mountainous perch is the impressive Monastery of Panayia Yiatrissa.

In 1770, after the Orlov Revolt failed, the Ottomans wanted to punish the Klephts for their support of it.