The cone of Vesuvius and its green slopes are the protagonists of one the most celebrated sights in Italy. The entire area of Vesuvius is of great environmental and scenic interest. The National Park of Vesuvius extends some 8,800 hectares and has a diverse presence of flora and fauna that populate the areas of the lava flows and surrounding woods. The definite lines separating the green areas which host over 900 species of plants and the arid, rocky areas around the crater create a unique environment. The Observatory of Vesuvius, built by the Bourbons and one of the oldest in the world, is only 2 km from the crater.