COPENHAGEN, Denmark (AP) — The Faeroe Islands, an 18-island archipelago midway between Iceland and Scotland, is closing for tourists for a weekend in April — unless they want to help locals keep the rocky isles clean and unspoiled.

Gudrid Hoejgaard, head of the local tourist board, says about 100,000 people visit the islands every year.

Hoejgaard said Wednesday that “tourism is not all about numbers,” adding that “our aim is to preserve and protect the islands.”

Some 100 visitors will be able to join the Faroese Maintenance Crew in exchange for free room and board in late April, when they will work with locals “to keep their green islands unspoiled.”

The windy islands, inhabited by about 50,000 people and 80,000 sheep, draw visitors to their dramatic scenery, with waterfalls and abundant birdlife.