Maria Island is a mountainous island off the east coast of Tasmania. The entire island is a national park and has a total area of 115.50 km², which includes a marine area of 18.78 km² off the island's northwest coast. The island is about 20 km in length from north to south and, at its widest, is about 13 km west to east. At its closest point (Point Lesueur), the island lies four kilometres off the east coast of Tasmania. The island was named in 1642 by Dutch explorer Abel Tasman after Maria van Diemen, wife of Anthony van Diemen, the governor general of the Dutch East Indies in Batavia. The island was known as Maria's Isle in the early 19th century.
For two periods during the first half of the 19th century, Maria Island hosted convict settlements. The island's first convict era was between 1825 and 1832 and its second - the probation station era - between 1842 and 1851. Among those held during the second era was the Irish nationalist leader William Smith O'Brien, exiled for his part in the Young Irelander Rebellion. His cottage still exists in the nearby former penal colony Port Arthur to where he was deported after his time on Maria Island.