My group had to locate the hidden entrance to an abandoned Gnomish city. They searched for two days before they found what they thought was the entrance. It was the entrance…., to Kiddieland, the Gnomish equivalent of a modern funhouse for children. Evil, nasty super-gremlins had infested the place and had warped much of the magic there to terrorize suckers, er, characters who found the way in.
A common mistake when writing adventures set in deserts is to assume that the climate is too ferociously hot to wear armor. Historically, most battles in deserts involved troops dressed in protective armor. Although they would have been miserable during the hottest part of the day or the hottest part of the year, desert weather isn't intolerably hot 24/7.