Question: When did the Zambia border re-open?
About the article "Victoria Falls", section "Zambia's independence and Rhodesia's UDI".

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In 1964, Northern Rhodesia became the independent state of Zambia.
The following year, Rhodesia unilaterally declared independence.
This was not recognized by Zambia, the United Kingdom or the vast majority of states and led to United Nations-mandated sanctions.
In response to the emerging crisis, in 1966 Zambia restricted or stopped border crossings; it did not re-open the border completely until 1980.
Guerilla warfare arose on the southern side of the Zambezi from 1972: the Rhodesian Bush War.
Visitor numbers began to drop, particularly on the Rhodesian side.
The war affected Zambia through military incursions, causing the latter to impose security measures including the stationing of soldiers to restrict access to the gorges and some parts of the falls.
Zimbabwe's internationally recognised independence in 1980 brought comparative peace, and the 1980s witnessed renewed levels of tourism and the development of the region as a centre for adventure sports.
Activities that gained popularity in the area include whitewater rafting in the gorges, bungee jumping from the bridge, game fishing, horse riding, kayaking, and flights over the falls.
The land west of the plateau road as it traverses the top is in Zambia, which also calls its portion Nyika National Park, comprising just 80 km².
As there is no other road, Zambians can only reach it via Malawi.
The Zambian park includes a colonial-era resthouse with splendid views west.
Once it was the only accommodation in either park, in those days people from Malawi staying there did not have to pass through any border formalities, but paid a "Zambia entrance fee" along with their accommodation bill.
The rest house closed in 1998, but re-opened as the "Nyika House" in 2006, available only to pre-booked tour groups. 
Lower education in Zambia is divided into three levels; primary, junior secondary and upper secondary.
Higher education is very limited and centred on the six universities of Zambia: University of Zambia, Copperbelt University, Zambia Open University, Cavendish University, Zambia Adventist University and Northrise University. 
Nyika National Park lies in the northeast of Zambia, on the western edge of the Nyika Plateau, which is one of the highest parts of the country and most of which lies in neighbouring Malawi.
As a consequence of the colonial era when both countries were administered by Britain, a cross-border reserve was established on the plateau.
After independence it was divided into the large Nyika National Park (Malawi) and the much smaller Nyika National Park (Zambia).
The border between the two parks is the north-south plateau road, which is the only road access, and it starts and finishes in Malawi.
Consequently Zambian visitors must enter Malawi to reach it (the nearest Malawian entry points are at Chisenga and Katumbi).
The Zambian side is undeveloped except for a colonial-era resthouse, built around 1946, which used to be the only accommodation in either park.
After independence, people from Malawi staying there did not have to pass through any border formalities, but paid a "Zambia entrance fee" along with their accommodation bill.
It closed in 1998, but was refurbished by a private tour company and reopened in 2006 as the "Nyika House", available only to pre-booked tour groups.
As they have already entered Malawi and there are no formalities and restrictions at the boundary between the two parks, visitors from Zambia usually also visit the facilities and features of the Malawian park.
Between September and April, a wide variety of wildflowers can be seen in the national park.
The Nyika Plateau and two smaller highland areas to the north are the only representatives in Zambia of the Southern Rift montane forest-grassland mosaic ecoregion.
For other details of the park environment and wildlife, see the Malawian park. 
Chirundi is a small town in northern Zimbabwe on the Zambezi River which is the border with Zambia.