Kurokabe means 'black walls', and you'll find plenty of them in this photogenic historic district (it's not really a square). Many of the old machiya (townhouses) and kura (storehouses) are now antique shops and galleries and studios showcasing the town's longstanding glass industry.
From Nagahama Station's east exit, follow the street to the left alongside Heiwado supermarket, and take the first left after Shiga Bank; Kurokabe Square begins about 100m further on.