A tall, four-sided pillar of stone, usually tapering, that terminates in a pyramid. Obelisks were often placed at the entrances of ancient Egyptian temples. They continued to be used as monuments in the Western world in the 18th, 19th and 20th centuries. Web resource here.

Obelisk_of_Thutmosis KarnakObelisk of Thutmose I, Karnak, Egypt. Rose granite. 1493/1492-1479 BCE.