Most people visit Greece to see its ancient ruins, idyllic beaches, and sweeping cliffs. Not Bernhard Lang. He goes for the fish farms.

Lang snapped this fascinating aerial of an offshore farm some 2,000 feet in the air last month. He loved the repetition of the circular and square cages, set like gems in the cerulean waters of the Mediterranean. “They look like abstract, geometric designs,” he says.

Greece has more than 300 marine aquaculture farms, mostly near the Dodecanese Islands, Ionian Islands and Euboea. In 2015, the industry raised at least 121,000 tons of sea bream, European bass and mussels. Farmers breed the animals in fisheries located on shore, then transfer them to ocean cages measuring up to 400 feet in diameter and housing up to 330 tons of fish each. The fish mature for a year or two before being harvested and exported to countries like Italy, France and the US.

Some criticize aquaculture operations for releasing waste into the environment and treating fish with antimicrobials, linked with the emergence of antimicrobial-resistant bacteria. "Mass animal farming—it’s not fun for the animals," says Lang. "On the one hand there’s this beautiful form, and on the other it’s not that nice."

Lang learned about aquaculture farming after a friend photographed a fishery in Norway from the ground. The aerial photographer's spent the last few years documenting everything from beach umbrellas to shipping containers and could easily envision how interesting the fisheries might look from above. A Google search told him Greece has one of the world’s biggest aquaculture industries, so after perusing some promising satellite imagery, he booked a ticket.

He arrived in Athens last month for a single 3-hour photo flight. As the pilot cruised the coastlines of nearby islands (Lang won't reveal which ones), Lang pointed his Pentax medium format DSLR straight down out the open door. He snapped some 1,500 pictures of about 25 fish farms, including this one. “They don’t look like how you see them in Google Maps,” he says. “I was even more impressed.” Not bad for a bunch of fish.