Halley 2 was officially sealed for the last time in 1982 by bulldozing the last remaining shaft in. It remained like this during 1983 (my first winter). There were a couple of semi-clandestine visits (I was part of the 2nd one) during 1984 before the BC banned further trips. In 1985 I believe there was a larger scale visit, including the recovery of some large pieces of brass bar (~8ft x 4in dia!) which had been considered impractical to recover when the base was sealed in 1982.
I certainly wasn't the last person to visit Halley 3, although I may be one of the last to sleep there. During a salvage trip in the 1984 winter the wind got up and we were obliged to spent the night there. This was actually quite comfortable as we were still able to start one of the main generators at that time so had light and heat. There must have been food around as well as I don't remember being hungry.
[30 May 2005]
See also, report by Mick Dixon.