Most visitors of Loutro know about the fortress of Koules, which even today dominates over the village. However, they are unaware of the existence of a second fortress which is very easily accessible. The fortress of Kastella is located south of the village and next to the harbor where the big ships from Chora Sfakion stop.
It was a small fort built on the cliff just opposite the islet Fanari of Loutro hosting a small lighthouse. Today, unfortunately, only the bases of the fortress are preserved, as most of the walls have collapsed. The site was strategic as it supervises the entire protected bay of Loutro.