Story setting

Alex and Lily stepped off the exquisite, super-tall space ship. As soon as they got off, their jaws dropped in amazement. They started walking cautiously, but then they saw an alien and ducked as quickly as a jet aeroplane. The alien looked ugly and slimy as a snake, he stopped and looked around mysteriously. Above them towered buildings taller than their eyes could see with needle like spikes ascending above them. As they continued walking the smell in the air penetrated their nostrils like smoke. Where were they?