When 'Little Kilauea' burst open in a fiery inferno in November 1959, it filled the crater with a roiling lake of molten rock fed by a 1900ft fountain that lit up the night sky with 2 million gushing tons of lava per hour at its peak. The lake took over 30 years to completely solidify. From the overlook, which you can drive to, you can view the spectacular mile-wide crater and wonder whether the trail traversing the middle is as astonishing as it looks. (It is.)
If you don't have time to do the Kilauea Iki Trail, you can get a tree-free photo op just a few hundred feet counterclockwise from the beginning of the trail.