We have seen them from a distance several times, and have yet to get up close and personal. Captain Cook didn't get close either. He saw them as he sailed up the east coast in 1770 and named them - apparently he thought they resembled glasshouses.
They 13 mountains are actually the remnants of volcanoes about 25 million years old, the plugs of molten rock have been exposed as the surrounds eroded away. The first photo was taken from the airstrip at Caboolture (where we went to see the one and only Beaufort Torpedo Bomber left from WW2, currently being restored by volunteers) and the second photo was taken from a lookout on the Mt Mee road.