Several historians said that was especially true under Mr. Putin, who once worked for the K.G.B., the secret police agency whose precursors created the camp. In Mr. Solzhenitsyn’s telling, the labor camp system was a secret police experiment that spawned a prolonged nightmare, “born and come to maturity on Solovki.”

In the long days of the Arctic summer, it is hard to picture the dystopian scenes described by camp survivors. The main island, covered by thick pine forests and dotted with lakes, has a bucolic if dilapidated air. Cows and goats graze freely outside the monastery walls, in a village with a year-round population of about 1,000.

The islands were considered sacred long before the monastery was built; pre-Christian cultures left behind complex stone labyrinths, built as portals to the afterlife. The monastery’s turreted granite walls were finished around 1601, and withstood a British naval bombardment during the Crimean War.

When Mr. Brodsky, 69, first visited the islands in 1970, many traces of the long-closed labor camp remained. An engineer and photographer, Mr. Brodsky began documenting it all. He tracked down camp survivors across Russia, at a time when even mentioning the Solovki gulag was taboo. The K.G.B. learned of his project and tried to get him fired.

After the Soviet Union collapsed and some archives were opened, Mr. Brodsky created an exhibit and wrote a book, “Solovki,” a 527-page compendium of documents, photographs and testimony from former prisoners.

Former prisoners told him that inmates worked 12 hours a day at arduous tasks like felling trees, often with little more than their bare hands. They wore whatever clothes they were arrested in, which eventually fell to rags. In the winter they slept in piles to ward off the icy cold; in the summer, the mosquitoes were so aggressive that one excruciating punishment was simply to be tied up naked outdoors. A remote church on Sekirnaya Hill became a “special punishment chamber”; few sent there returned.