   thumb|mount lidgebird and mount gower, twin mountains to the south of lord howe islandthumb|view of the lord howe island lagoon, a part of the lord howe island marine park lord howe island marine park is the site of australia's and the worldâs most southern coral reef ecosystem. the island is 10&nbsp;km in length, 2&nbsp;km wide and consists of a large lagoonal reef system along its leeward side, with 28 small islets along its coast. in 1999, the waters within three nautical miles of lord howe island (465.45&nbsp;km2) were declared a marine park under the nsw marine park act 1997 to protect its unique marine biodiversity, with the park currently being managed by the new south wales marine parks authority. both lord howe island and balls pyramid are incorporated within the three nautical miles protected by the state marine park. the waters from 3 - 12 nautical miles were declared a federal marine park on 21 june 2000, see lord howe island marine park (commonwealth waters). both marine parks complement the island's status as a world heritage site. lord howe island is located approximately 610&nbsp;km off the eastern coast of port macquarie, new south wales, australia (31Â°33âs, 159Â°04âe). lord howe island is remote, has a biologically diverse marine system with a high degree of endemism. lord howe island marine park was declared after it was recognised as an area with outstanding natural values, an extraordinary array of marine habitats and biodiversity, rich maritime cultural heritage and social and economic importance to the island community, giving it both national and international importance.{{cite journal|last=nsw marine park authority|title=lord howe island marine park: zoning plan review report,|year=2010|url=http://www.mpa.nsw.gov.au/pdf/lhimp-zp
IUCN_Category_VI Lord_Howe_Island Marine_parks_of_New_South_Wales Parks_in_New_South_Wales Visitor_attractions_in_New_South_Wales World_Heritage_Sites_in_Australia