In Frasier's apartment there is a telescope. Frasier bought this for Martin when Frasier was concerned that his father was doing nothing other than sitting around the house all day.  The telescope first appeared in Episode 5 "Here's Looking At You" and has remained ever since.

Martin was very pleased with the gift, saying he could watch a pair of nesting falcons with it. However he soon finds Irene, a woman in the opposite skyscraper who also has a telescope. Using notepads and pens, they start a long distance friendship. Frasier teases him about this and gets Irene's telephone number so they can actually speak. Although he is at first reluctant to the idea, Martin does eventually go out on a date with Irene, although we never find out how it went.

Frasier and Niles also once used it to spy on other skyscrapers - but they were admiring some furniture, much to Martin's disappointment.

The telescope also helped play a part in the destruction of Martin's chair, as the sunlight reflected through the telescope onto the chair and caused it to burn...