The 70 islands of the Whitsunday group are some of the best known and most developed Barrier Reef islands and are scattered on both sides of the Whitsunday Passage, within 31 miles of Shute Harbour, jumping-off point for the many cruises through the group. The actual Great Barrier Reef is at least 37 miles out from Shute Harbour; Hook Reef is the nearest part of the reef. Many of the Whitsunday islands are National Parks. The large block of mainland national park opposite them, stretching from Airlie Beach south to Conway, is known as the Conway Range National Park.