Why is Death in Venice set in Venice?
One of the central themes of this excellent short story is the way in which pursuing eroticism, as symbolised in the figure of Tadzio, and relinquishing restraint and reason, can lead to death. Note how von Aschenbach for example deliberately chooses to stay in the city in spite of the cholare epidemic and the threat of death. Throughout the story, a relationship between eroticism and death is created, and this is supported by the setting. Venice is a city that is famous for its sensuous symbolism, yet it is also a city that is well known to be decaying and dying year by year. Note how the text itself connects this too ideas in the city of Venice:
Is there anyone but must repress a secret thrill, on arriving in Venice for the first time--or returning thither after long absence--and stepping into a Venetian gondola? That singular conveyance, come down unchanged from ballad times, black as nothing else on earth except a coffin--what pictures it calls up of lawless, silent adventures in the plashing night; or even more, what visions of death itself, the bier and solemn rites and last soundless voyage!
Note how this quote combines the excitement of probably illicit sexual adventuring with death in the imagination of the protagonist. Thus setting the story in the city of Venice helps to emphasise the important thematic relationship between sex and death.
Venice is a dreamscape in which Aschenbach goes to die. The city symbolizes death, beauty, and decay. The following quote captures the mixture of dream ("fairytale"), decay ("art used to blossom . . . "), and death ("putrid atmosphere") of this city. Aschenbach sees Venice as, like death itself,
alluring and dubiously entrancing—this city, part fairy tale, part tourist trap, in the putrid atmosphere of which art used to blossom luxuriously and which had inspired musicians with lulling melodies . . .
Venice transports Aschenbach into a dream world in which he can engage in increasingly obsessive and idealized fantasies about a beautiful young boy he doesn't know—it is, as many critics have noted, a means for Aschenbach to escape from his prosaic, controlled home and into the Dionysian—the world of decadence and desire.
Venice is also Aschenbach's place of transition into death. With all its waterways, it functions as the river Styx, ferrying the older man to the other side. This function is emphasized, for the gondolas are likened to coffins, and Aschenbach is rowed into and around the decaying city by gondoliers who, like the ferryman Charon in classical mythology, have an outsized role as supporting cast in this novella.