Aside from the 20th-century addition of the Bois de Boulogne, the Bois de Vincennes and the Paris heliport, Paris's administrative limits have remained unchanged since 1860. A greater administrative Seine department had been governing Paris and its suburbs since its creation in 1790, but the rising suburban population had made it difficult to maintain as a unique entity. To address this problem, the parent "District de la région parisienne" ('district of the Paris region') was reorganised into several new departments from 1968: Paris became a department in itself, and the administration of its suburbs was divided between the three new departments surrounding it. The district of the Paris region was renamed "Île-de-France" in 1977, but this abbreviated "Paris region" name is still commonly used today to describe the Île-de-France, and as a vague reference to the entire Paris agglomeration. Long-intended measures to unite Paris with its suburbs began on 1 January 2016, when the Métropole du Grand Paris came into existence.