Of great importance are the extensions of sea-grass, a marine plant that thanks to the transparent of the water lives here to depths of more than 40 meters. The integrity of the marine environment of ventotene and Santo Stefano is guaranteed by the Ventotene and Santo Stefano Protected Marine Nature Reserve. Divided into three areas with different degrees of protection, here the balance built up over the centuries by nature and the environment can be maintained: the Total Reserve cvers the zone biologically most intact and access is limited and allowed solely for scientific purpoes; in the General Reserve human intervention is allowed only in total respect of the natural integrity and access is at set points along fixed routes; the Partial Reserve has a major human presence and all activities that are compatible with the conservation and protection of the environment are permitted.
Ventotene is another small administrative area in the small archipelago. It is about 1,3/4 miles long, and just over half a mile wide at the widest point; it reaches an altitude of only 4,280 ft at Monte dell' Arco it is quite different in character to Ponza. More compact, its volcanic origin can be seen from the reddish - brown soil, covered with shrubgrowth and cactus. This is where the beautiful daugther of Augustus, Jiulia Agrippina the wife of Germanicus, and Octavia the barren wife of Nero lived in exile. The remainds of imperial villa stand near Punta Eolo. The church, dedicated to St. Candida, dates back to 1765 and was designed by Winspeare. A tour around the island will bring many surprise, beginning at Punta Eolo with its typical low vertical rocks in the form of parallelepiped: Gala Rossana, with its tiny port for motorboats the beach, the "grottoes"; the tufa stone at Punta del Pertuso, where the little Roman port was built with its quay - sides topped by attractive natural tufo - stone arches; the tiny beach of Gala Nave with two cliffs called Nave di Terra and Nave di Fuori; then there are Punta dell'Arco, Punta Pascone, Gala Parata Grande with another small beach, and the Sconcigli cliffs. The charming little town, with its simple clear colours, represents a typical mediterranean settlement. It can be reached from Formia (and Anzio in summer).
Santo Stefano - Just over 1 nautical mile from Ventotene is the isle of Santo Stefano. Circular in shape, with a surface area of 28 ha, its silhouette is dominated by the massive penitentiary built in 1795 with a panopticon structure and according to the principle of "one mind over another"; it was used until 1965, when it was abandoned as a prison for life prisoners. The totally uninhabited island is popular for excursions and only has small landing stages and access depends on the direction of the wind; the main one is called Marinella and faces Ventotene.