50. Walnut Canyon National Monument
> Average annual visitors: 129,914
> Location: Arizona
> Established: 11/30/1915
> Purpose: Protects 800-year-old Sinagua cliff-dwellings.
49. Johnstown Flood National Memorial
> Average annual visitors: 131,139
> Location: Pennsylvania
> Established: 8/31/1964
> Purpose: Memorializes victims of the town’s 1889 flood.
48. Lava Beds National Monument
> Average annual visitors: 131,625
> Location: California
> Established: 11/21/1925
> Purpose: Marks North America’s largest concentration of lava tube caves.
47. George Washington Birthplace National Monument
> Average annual visitors: 132,018
> Location: Virginia
> Established: 1/23/1930
> Purpose: Marks birthplace of America’s first president.
46. Perry’s Victory & International Peace Memorial
> Average annual visitors: 135,530
> Location: Ohio
> Established: 6/2/1936
> Purpose: Commemorates U.S. naval victory and lasting peace between Britain, Canada, and U.S.