DioptraSave
The earliest dioptra (c.300 BCE) was a device for measuring the angle, in parts of a "Sign", between two celestial objects. Photos and descriptions of how to make one and how they work. http://members.tripod.com/Bluestar_4/...
Stones of WonderSave
A guide the megalithic monuments of Scotland and their astronomical alignments. Also contains illustrations, a bibliography and suggestions for the best times of year to visit. http://www.stonesofwonder.com/