Parks Canada designated Earnscliffe a National Historic Site of Canada.

"The designation refers to the house and the grounds." Parks Canada.

More National Historic Sites of Canada that are located in Ottawa:

Aberdeen Pavillion

Beechwood Cemetery

Billings House

Central Chambers

Central Experimental Farm

Chateau Laurier

Confederation Square

Connaught Building

Former Dominion Archives/Canadian War Museum-Sussex Drive

Former Geological Survey of Canada -Sussex Drive.

Former Ottawa Teachers College

Langevin Block 

Laurentian Club/John Booth Residence

Laurier House

Maplelawn and Gardens 

Notre-Dame Roman Catholic Basilica-Sussex Drive.

Parliament Buildings

Rideau Hall and Landscaped Grounds -Sussex Drive.

Royal Canadian Mint-Sussex Drive.

Victoria Memorial Museum

Ottawa/Kingston Rideau Canal.

National Historic Sites Act 1998.

Preamble - And whereas it is in the national interest (a) to protect the nationally significant examples of Canada's natural and cultural heritage in national parks, national historic sites, national marine conservation areas and related heritage areas in view of their special role in the lives of Canadians and the fabric of the nation.

Meaning and importance of the term "Ottawa's Mile of History".