Marotiri
Marotiri is a group of four uninhabited volcanic rocks protruding from the sea, forming the southeastern end of the Austral Islands of French Polynesia. Marotiri is also known as Bass Rocks, after the European explorer George Bass who discovered them in either late 1801 or early 1802 but whom had since erroneously deemed them the long lost Four Crowns of Quiros:
“ Sailing North for Tahiti I found The 4 Crowns of Quiros, placed on the modern charts. I found their position to be 14 leagues E.S.E of Oparo . Of all discoveries this one gave me the most pleasure as it serves to redeem the name of a great Navigator from the infamy of having been called a liar. It is true that these 14 leagues do not correspond with Quiros's said 4 league distance but I think this to have been on account of a copy error by the one who transferred his manuscript and that 4 should have been 14. This is why Vancouver’s Oparo is the San Miquel of Quiros. When I saw the rocks and the island to the West I had no idea that the last one was Oparo, because having run a lot of sea by this time and not expecting to find myself to be close to it I thought both rocks and island to be discoveries. But having had the fortune to observe both latitude and longitude to be in accordance with Vancouver’s Oparo I do not doubt it to be the same island.”
Marotiri is very isolated, located about west-south-westward of Pitcairn Island. The closest island is Rapa Iti, 75 km farther northwest, but separated from it by an ocean depth of more than 1,500 meters. The rocks are part of the municipality of Rapa.
The climate is wet temperate. The lower rocks are almost devoid of vegetation - although there is some vegetation on the upper slopes and summits. They are important as a seabird rookery. Fish abound in the adjacent waters. The rocks emerge from a submarine platform 100 meters deep and 5 km in diameter. They lie at a distance between 1.5 and 3 km from one another. The total land area is 43,100 m2, which is broken down as follows by the individual rocks:
| Rock | Area |
| Northern Rock | 5,800 |
| Central Rock | 1,800 |
| Southern Rock | 22,400 |
| Western Rock | 13,100 |
| Marotiri | 43,100 |
The southern rock is the largest, with a height of 113 meters at its highest point.