An obelisk (Latin obeliscus, from Greek obelískos) is a tall, usually slender stone pillar, quadratic in cross-section and narrowing towards the top, ending in a pyramidal capstone (pyramidion). In 16th and 17th-century terminology, the words obelisk and pyramid were interchangeable. There is also the umbrella term meta, which denotes the conical columns in the ancient circus, positioned at the turning points at the ends of the spina (the central wall to be rounded by t…