Henges are only one type of astronomical tracking and observation monument. Other kinds include using big rocks that already exist and then building something close enough to observe its interaction with the Sun; building an observatory or a big pyramid; constructing something that interacts with the sun in a very quiet, private way; or hauling a big heap of strange rocks in the middle of the chalk uplands of England (hello, Stonehenge!). Hear me read a bunch of quotes from archaeoastronomers about what their profession is, too!