a normal xyz 20mm calibration cube but with a city on the inside —

Founded a normal xyz 20mm calibration cube but with a city on the inside models & stl files for printing
XYZ 20mm Calibration Cube
iDig3Dprinting
Calibration cube
Davis543
Voronoi CUBES
Kazzee
Plant pot but insideout
DanielOnneweer
5x5 Rubiks Cube
saulquinn
Vase with Ring
Star Blink