In the pre-Internet days I made a sundial for the garden. Of course you
can buy sundials, but the ones you buy are simply decorative. A "proper"
sundial has to be made for a specific place, taking into account the
latitude and, if it is to go on a
wall, the wall "declination". Creating that first sundial required some
complex calculations using equations I found in a book from the public library. Nowadays, there are Internet sites
that will not only find the exact latitude and longitude for any place,
but will do all the calculations you need and design a sundial for any
spot you have in mind! So I have just made a new sundial for the garden.