The triple point of pure water is at the temperature just above freezing (0.01° C) and at the pressure (0.006 atm) at which it can exist in equilibrium in all three states: liquid, solid, and gaseous.
Yes, water can freeze & boil at the same time!
The triple point is used to calibrate thermometers.
Winding backroads to Morgan Hill and Gilroy along Calero Reservoir south of San Jose are fun for motorcycle riders, and across the water are trails ideal for mountain bikers.
—and no one knows how many millions of ages before
—the great whales should have been spouting all over the sea, and sprinkling and mistifying the gardens of the deep, as with so many sprinkling or mistifying pots; and that for some centuries back, thousands of hunters should have been close by the fountain of the whale, watching these sprinklings and spoutings
—that all this should be, and yet, that down to this blessed minute (fifteen and a quarter minutes past one o’clock P.M. of this sixteenth day of December, A.D. 1851), it should still remain a problem, whether these spoutings are, after all, really water, or nothing but vapour
—this is surely a noteworthy thing.
–Moby Dick; or, The Whale (Chap. 85: The Fountain) by Herman Melville