The Groma is an ancient surveying instrument used by the Romans for land measurement and construction. It consists of a horizontal crossbar mounted on a vertical staff, with plumb lines hanging down to ensure accurate alignment. This tool allowed surveyors to create straight lines and right angles, essential for building roads, aqueducts, and other structures. The Groma played a crucial role in Roman engineering, enabling precise planning and execution of large-scale projects. Its design influenced later surveying tools and techniques, highlighting the importance of accurate measurements in construction and urban planning throughout history.