The National Park Service is the U.S. federal agency that manages the national park system, which covers more than 85 million acres in 433 park units. These include national parks, monuments, historic sites, military parks, battlefields, memorials, recreation areas, scenic waterways and seashores in every state. It shares the stories of places and people through history, nature, education and multimedia resources for visitors, kids and teachers. It also plans and maintains the roads, trails, bridges, ferries and transit that give people safe access to the parks, and it invites artists to find inspiration in the nature, culture and history the parks preserve.