"It is both wild and picturesque. You know that you will have exciting and varied adventures here, all in a relatively safe environment," he said one warm summer's evening on his sailing boat in the port of Nynashamn.
Klas Helmersson, the former director of the Vasa Museum in Stockholm that exhibits the only intact 17th century ship ever salvaged, said it was the combination of moving on water and the inherent allure of the islands that has made him sail the archipelago for more than 30 years.
"It is the fascination of always discovering new things and the contrasts between the sea and the islands," he said, adding that his favorite place is the barren, "somewhat forbidding" outer portion of the northern archipelago around the islands of Rodloga and Svartloga.
The nature has also long inspired Sweden's painters, writers and filmmakers. Ingmar Bergman filmed "Summer with Monica" on the island of Orno, and the "Seacrow Island" books, by "Pippi Longstocking" writer Astrid Lindgren, were adapted to the screen on Norrora.
August Strindberg, one of Sweden's most famous writers, lived on the island of Kymmendo in the 19th century, and not only wrote about its inhabitants in the national epic "Natives of Hemso", but also painted its grim and grey winter storms.
It might seem strange that the Stockholm archipelago was unwelcoming to foreigners for so long, but perhaps it's not surprising considering its history. The fear of a sea invasion was sparked by a Russian attack in 1719 that erased entire fishing villages and farming communities. It was further fueled by World War II and the ensuing Cold War.
The 16th century fortress town of Waxholm, dubbed "the capital of the archipelago," gives testimony to this threat. The Waxholm Citadel and Fortress museums show the development of the Swedish defense in the archipelago during the last 500 years. Close by, Siaro fortress museum exhibits cannons and trenches above ground, and a center of command, kitchen and barracks below ground.
In a secret program during World War II, Sweden even used the island of Galo to train seals, otters and eagle owls to detect submarines and prime explosive devices.
But these days there is little concern over a Russian invasion, Grape said.
"The only real invasion we are seeing today is the pilgrimage of tourists to the island of Sandhamn," she said pointing to the interest in the internationally best selling crime novels by the late Swedish journalist Stieg Larsson.
Larsson's protagonist has a fictitious summer house in an old missionary station in the picturesque sailing hub of Sandhamn -- apparently enough to attract visitors from other shores.
Grape expected a planned U.S. screen adaptation of the books would only increase the interest in the archipelago.
"A Hollywood film would certainly put the archipelago on the map. I think we can expect even more foreigners in the future."