The utilization of lime mortar to connect the masonry wall elements of historical architectural structures, to overlap and protect these structures, is an ancient technique that has prevailed until today as a compatible solution based on the principles of restoration. In recent years, scientists have studied the modification of lime mortars with new, sustainable and environmentally friendly materials that respect the value of monuments and are aligned with the principles of restoration. In the present study, the existing international literature on advanced lime mortars with improved mechanical and physicochemical properties is presented, and the knowledge gap is identified. Finally, new materials for improving lime mortars are proposed as a basis for successful restoration and further protection of architectural heritage.