| Synsiä | |
| Pushpin Map: | Finland |
| Coords: | 62.0833°N 56.5°W |
| Catchment: | Kymijoki |
| Basin Countries: | Finland |
| Area: | 19.273km2 |
| Shore: | 84.35km (52.41miles) |
| Elevation: | 110.4m (362.2feet) |
| Frozen: | December–April |
Synsiä is a medium-sized lake in Southern Savonia, Finland.[1] The lake is quite shallow. It is located in Kangasniemi municipality near the Finnish National Road 13. From the road there is a nice scenery to the lake and the farms around it.