There is none on the mainland, but one island owned by Australia, Macquarie Island, does have some. It is over 1000 miles from the Australian mainland.
The external territory of Australia that is furthest from the mainland is Christmas Island, located in the Indian Ocean. However, the territory that is geographically the farthest from the Australian mainland is the Cocos (Keeling) Islands, also in the Indian Ocean, situated about 2,200 kilometers (1,367 miles) northwest of Perth, Western Australia.
There is no island 300 miles south of Melbourne, Australia. The nearest any island comes to being in this location is Tasmania, Australia's island state. The distance from Tasmania to the closest point on the Victorian mainland is around 240 km, which is about 150 miles.
Block Island is 13 miles south of mainland Rhode Island.
The distance from Perth to Christmas Island is 2,594 kilometres, or 1,612 miles. This is about 1,400 nautical miles.
Catalina Island, Dominican Republic, or Isla Catalina, Republica Dominicana is located 1.5 miles or 2.4kms from the mainland.
Catalina Island, Dominican Republic, or Isla Catalina, Republica Dominicana is located 1.5 miles or 2.4kms from the mainland.
Christmas Island's area is 52.12 square miles.
Roanoke Island is located off the coast of North Carolina and is separated from the mainland by the Albemarle Sound to the north and the Roanoke Sound to the south. The distance between Roanoke Island and the mainland varies, but it is generally around 1 to 4 miles, depending on the specific location on the island and the nearest mainland point. The island is accessible by bridge from the mainland, making it easy to visit.
It is 52 Square Miles.
Sakhalin Island is located about 9.3 kilometers (approximately 5.8 miles) off the northeastern coast of the Russian mainland, separated by the Nevelskoy Strait. The island stretches approximately 948 kilometers (589 miles) in length and is the largest island in Russia. Its proximity to the mainland makes it accessible by ferry and other means of transportation.
Russia has the worlds longest border at over 35000 miles. From East to West Russia spans for 5592 miles.