One of Curtis's earliest memories of working with stone comes from his childhood, as a young boy destroying his father's drill bits in a failed attempt to pierce a stone. Many years later, Key to the Sea represents an early exploration of making rectilinear holes in stone. The slab of slate stands upright on a granite base. The hole forms a, "lens that might be used to examine the history that's evident from the interior of the hole," said Curtis.
"The point is to sometimes look into the stone, sometimes through it."