I took these pictures in back my house in Lockport which is located at the top of the Niagara Escarpment. The pictures show a large "volcano" of ice up on the escarpment. I think that it was formed during the past few weeks of sub-freezing temperatures. It looks like there is an artisian well at the top of the hill and the water froze around it. The relatively warm water kept coming up through the cone and continued to build the ice formation.
The ice is approx. 12-14 feet tall at the highest point. If you look at the second picture, the opening in the cone is big enough that I could stand inside and have 4 feet of ice over my head.
All of the trees around the formation are 20-40 feet tall, mature trees.