The Obelisk Gatepiers in Limetree Walk, Alloa, were designed in the early eighteenth century as a key part of the Earl of Mar's Alloa Tower designed landscape, one of the most important historic landscapes in Scotland. The obelisks were important symbols and originally stood at the end of the earl's grand avenue. After our conservation audit established that the south obelisk was in a dangerous condition, we took the professional lead in the Historic Scotland grant aided project for their repair and restoration, which included completely rebuilding the obelisk on a new foundation, stone replacement, metalwork conservation (replacing the 5 rusted iron balls which supported the S obelisk, and pins), removing graffitti and total repointing using lime based mortars. We included researching and recording the structure and arranged for mortar and paint analysis to be carried out, revealing that hydraulic lime mortar was used for rebuilding the obeliks when they were moved to their present location, and they had been limewashed to blend with other later features.