The Spiegel- en Blijkpolderplas is a lake located near Nederhorst den Berg in the province of Noord-Holland, managed by Natuurmonumenten. The water body is characterized by open expanses of water interspersed with small islands, idyllic sandy beaches, and bordering marsh forests, making it a notable natural area in the Gooi & Vecht region.

The lake supports a variety of water and reed birds. Species recorded here include brilduikers (Barrow's or common goldeneye), nonnetjes (smew), krooneenden (red-crested pochard), and rietzanger (sedge warbler), reflecting the richness of the surrounding wetland habitat. The combination of open water and reed-fringed edges provides varied paddling scenery as one moves around the lake.

Photographs of the area show small boats out on the water, indicating recreational boating takes place on the Spiegelplas. A 10-kilometer walking route, the Rondje Spiegelplas, circuits the lake and passes all of its main features, which gives paddlers a sense of the lake's overall scale and the variety of landscapes along its shores. The route is marked with blue arrows by Natuurmonumenten.

The lake has been recognized as one of the notable natural areas of Noord-Holland. Paddlers should be aware that the site is a protected nature reserve managed by Natuurmonumenten, and any applicable regulations regarding paddling or access should be confirmed directly with the managing organization before visiting.