still working as an assistant gardener, in spring 1816 Lenné received a commission from the Prussian Chancellor Karl August von Hardenberg to renovate the grounds around his country house at Klein-Glienicke. This work on Glienicke Palace, which would later become Prince Carl of Prussia's residence, laid the groundwork for Lenné's designs for the surrounding area of Potsdam, which he wanted to turn into a Gesamtkunstwerk. The upgrades of the Glienicke grounds were followed - in close cooperation with the architects Karl Friedrich Schinkel, Ludwig Persius, and Ferdinand von Arnim - by those of others such as the Böttcherberg and facing it Babelsberg Park, which was completed by Prince Hermann von Pückler-Muskau. Characteristic of Lenné's work are versatile sight axes - a horticultural stylistical device - which he applied at Sanssouci Park and elsewhere. As part of the Berlin-Potsdam cultural landscape, which stretches from the Pfaueninsel to Werder, many sites of Lenné's work are World Heritage Sites and have been under the protection of UNESCO collectively since 1990. Prussian Garden Director-General The accomplishments of the garden architect are reflected in his career progression. In 1818 he was an employee of the Royal Garden Authority, and in 1822, he received a promotion to Gardening Director. That same year, Lenné became a founding member of the Prussian Society for the Promotion of Horticulture. Lenné also accepted the position of Manager of the Division of Orchard Cultivation and later of the Parks Division. In 1823, the Gardener Academy in Schöneberg and Potsdam was founded under his management. Here garden architecture was taught in a scientific manner for the first time. In 1828, Lenné was named the sole Garden Director and in 1845, Prussian Garden Director-General. The Prussian Academy of Arts made Lenné an honorary member. In 1840, the recently enthroned King Friedrich Wilhelm IV assigned the urban planning of Berlin to Lenné. One of his most important achievements in this role survives in the building of the Luisenstadt Canal, constructed in 1852, between the Landwehrkanal and the River Spree in Kreuzberg. The canal's design was based on plans by Chief Building Officer Johann Carl Ludwig Schmid. In the 1850s, he advised on the planning of several cities, including Dresden, Leipzig and Munich. Despite centering his life around Potsdam and Berlin, Lenné remained attached to his Rhenish homeland and contributed to the further beautification of Koblenz, particularly in the Rheinanlagen, which was under his management