The stone town of Zanzibar, Tanzania, lost its continuity when the Arab ruling class forfeited power after independence (December 1963). Yet, argues the author, efforts to preserve it should be encouraged, because destruction of its outstanding architectural heritage would deprive the present culture of the possibility of defining itself against the past. Reviews the conservation programs in action: UNCHS, a Tanzanian government-sponsored project; and another financed by the Aga Khan Cultural Fund.