On a budget, weigh it — Teleférico de Madrid isn't cheap for what it is.
~€6 one-way / €9 return
A nostalgic, low-key joyride with nice aerial views over the city's western greenbelt and rooftops, fun with kids. The catch is it deposits you in the middle of Casa de Campo with little right there, the cabins are dated, and it can close in bad weather or off-season.