First steps - references

The idea for the environment is an ancient sci-fi city. It is located on a planet like Caladan (from Dune). The environment is mainly centered around rain, a common feature of this planet's meteorology. As a result, the landscape is scattered with rivers and mountains and hosts a diverse and complex underwater ecosystem. I would like the color palette to consist of shades of gray and dark green. Heavy, brutalist, yet without brutalist shapes, more streamlined as in art nouveau. Due to the frequent occurrence of heavy rainfall, the materials are mainly concrete and glass.