By day, lighthouses often serve as landmarks for ship captains seeking to identify their position along a coastline. Thus, lighthouses vary in shape, size, and color. Lighthouses can be square, round, conical, rectangular, and even octagonal (eight-sided). Some are painted with identifying stripes, spirals, or diamond patterns. Some have twin, and in one case triple, towers. Most lighthouses range in height from 10 m (33 ft) to 63 m (208 ft). Lighthouses are built from wood, stone, brick, reinforced concrete, iron, steel, or aluminum. They are designed to withstand local environmental conditions. For example, tall skeletal lighthouses located in the Caribbean offer less surface area to hurricane-force winds and waves. Lighthouse designs often reflect architectural styles of the time the lighthouses were built.