Crossword clue: Frozen spikes, often seen at Niagara falls in winter

Icicles are long, pointed pieces of ice that form when water drips and freezes. They are commonly seen hanging from roofs and cliffs, especially in cold weather. At Niagara Falls in winter, the mist from the falls can freeze and create many beautiful icicles. This makes "icicles" a perfect answer for the clue about frozen spikes at Niagara Falls.