Blackburn Lake Sanctuary has a very special type of sundial located beside the playground in the picnic area. A sundial is a type of outdoor clock. Sundials are usually flat, round disks with numbers and a pointer (or gnomon) that casts a shadow (when the sun is shining). As the sun moves across the sky, the shadow moves across the numbers, and the sundial shows the time of day.

Our sundial is called an analemmatic sundial. It uses a person’s body as the gnomon to cast a shadow onto the hour markers and reads true time. There are blocks, or bricks, on the ground with the names of the months on them. If you stand at the appropriate point, your shadow will fall on the markers on the low semi-circular wall. Where your body casts a shadow is the current time - you can even calculate daylight savings time.

There is a brochure on the notice board at the Visitor Centre with more information about the mathematical calculation that was required to position this sun clock.