The area of Agia Irini in Spilia is crossed by Keratos River, which has water till summer. The area hosts some waterfalls, most notable being the waterfall of about 4 meters in the river, just after the great aqueduct of Agia Irini. The rest of the waterfalls are formed at the side streams falling in Keratos, which however have water after intense rainfalls.
The most impressive cascade of the area is in the last part of the Kato Archanes torrent and just before meeting the River Keratos and the watermills of Agia Irini. It is about 7 meters high and is the last of a small series of successive descents. The water passes along the edge of the cliff, and during very high rainfall it forms a unique water curtain that falls in front of a small cave.