Anything can be created out of concrete. From beautiful old growth Douglas Fir trees with slides hidden in them to structural beams textured to look like totem poles. We frequently take real fossils and embed them into the carved rock to "tell a story". Earthen clay banks can be created with layers of sediment and aggregates to show how the geological process works. Literally, your imagination is the limit.
Crawl through Fir with safety surface,... or crawl over Fir.