My family and I are planning a visit to Niagara falls from the USA side. Is it possible to walk over to Canada and back? We are travelling with South African passports, ie, do we need visas for Canada?
According to this website (which anyone can use to determine if they need a visa), you will need a visa to cross over to Canada. You can walk to cross the border, but the entry requirements are no different than if you drive across or take the train. (People who fly into Canada from most visa-exempt countries also need an eTA, an electronic travel authorization, but these are not required for land crossings.)
The view of the falls is really spectacular on the Canadian side, so I'd recommend getting one. You can see the falls from the US side, but the angle isn't as good.
There are secondary falls (Bridal Veil and the American falls) which are also easier to see from Canada, but you can get a different but very spectacular view by walking on the bridge to Goat Island on the US side.