This is a restaurant with a nice lake view, the only one in the area at my knowledge. Indeed, due to the average quality of service and food, it is rather to be used for drinks and refreshments before boarding a boat for a lake tour.
The restaurant is just below the monastery at Matka Canyon -- it serves traditional Macedonian food, but to be honest, I've used it mostly for a cool drink on hot summer days:)
The sign is for an ecological summer school that was being held at Matka in summer 1999.
You can see the aluminum boat that is used to take tourists out on the lake.