To the Editor : Regarding '' Lviv , Ukraine : Heritage Survives a Complicated Past '' -LRB- Next Stop , July 23 -RRB- , it surely must be naivete on the part of the Travel section that in celebrating Lviv 's jolly inhabitants and its fascinating architecture , and enumerating its complicated past , the article omits the inclusion of the Janowska labor and extermination camp where tens of thousands died , in the custody of the Nazis and their enthusiastic Ukrainian collaborators .