The Armillary, an astronomical sphere of rings, shows (amongst other things) the path of the sun throughout the day, night and changing seasons.
The observer stands within the 2.5m diameter sphere constructed from wrought iron, from where the actual rising, meridian (am/pm) crossing and setting positions of the sun can be seen.
Three rings trace out these movements for summer, winter, spring and autumn. A horizontal ring acts as the horizon.
These rings are able to rotate allowing the observer to 'travel' from pole to equator, instantly comparing the path of the sun for any location on earth. The sphere may also be used to follow the moons orbit at its different phases, locate circumpolar stars and act as a sundial. Pretty cool!
(It also doubles up as a giant gerbil wheel)