According to Aki:
Hermit crabs are selective in choosing their shelters. Therefore, I decided to CT scan and capture the detailed 3D images of the unoccupied seashell which one of my hermit crabs had abandoned. Based on those images, I modified and slightly enlarged them with a 3D modeling software, and then produced several types of shelters with a rapid prototyping system. Finally I gave those shelters to my hermit crabs.
The cityscapes vary from the Empire State Building to Holland wind mills. After watching the below video, take a look at Aki’s website where he displays more of his shell artwork.