This could be an objective piece or simply a monument in the center of a city. I envisioned it being used in Sci-Fi settings but I also see that it resembles some pieces of public art found in Middle Eastern cities.
The bottom hex is 5" across flats and the entire structure stand about 6 1/2" tall.
Based on it's size I think it's suitable for use in scales from 10mm to 15mm. It could even work in 20mm, it would just be a smaller monument.