Inspiration: I think these are sort of Aztec inspired, although not by anything directly. They remind me a little of Mysterious Cities of Gold.
The bottom photo shows the work of the entire grade 4 (very small school) on display in the front office. We were inspired by the first bit of Spring sun we have started getting. The students cut circles from thick cardboard and decorated with oil pastels, ink, glue, gold paint and glitter.