Where have you gone, Zeus and Thor?

In ancient days, Zeus was the chief of gods in Greece and
everyone in that region believed and prayed to him. Centuries
later, Thor was the chief of gods in the viking world.
Along the path of humanity, there have been many, many other
gods and godesses from fire, to the sun, to pharoahs and kings,
and on and on and on.
Are there people today who still believe in some of those
supplanted gods of the past? Is there an active Zeus temple somewhere?
Or a Thor church? Or maybe a Druid meeting hall? A Mayan corn god altar?
Recognizing humans and their needs and habits, would it be
surprising if some or all of the old faiths somehow perservered?