The stadium is an important historic landmark. The lake is a National Historic Landmark. It is a National Historic Landmark. It has been designated a National Historic Landmark and National Monument. Scotchtown Plantation is a National Historic Landmark. It is designated a National Historic Landmark. The Lowell Observatory is a National Historic Landmark. It was declared a National Historic Landmark in 1985. It has been designated a National Historic Landmark. It is designated as a National Historic Landmark. It is now a National Historic Landmark. It has been designated as a National Historic Landmark. It was designated as a National Historic Landmark in 1986. The gate is a designated U.S. National Historic Landmark. It was designated a Registered National Historic Landmark in 1968.