At 345 feet (105 m) above mean sea level, Britton Hill in northern Walton County is the highest point in Florida and the lowest known highpoint of any U.S. state. Much of the state south of Orlando is low-lying and fairly level; however, some places, such as Clearwater, feature vistas that rise above the water. Much of Central and North Florida, typically or more away from the coastline, features rolling hills with elevations ranging from . The highest point in peninsular Florida, Sugarloaf Mountain, is a peak in Lake County. Much of Florida has an elevation of less than , including many populated areas such as Miami which are located on the coast. Miami and other parts of south Florida are the most vulnerable regions in the world to rising sea levels associated with climate change. Due to the vast amounts of limestone bedrock that Florida sits above, water is allowed to move relatively freely beneath dry land and to rise up to the surface. Water will also likely encroach from the Atlantic Coast and the Gulf Coast, and up through the Everglades, endangering the plant biomass within its marsh communities .