UPM (Universidad Politécnica de Madrid) is the Technical University of Madrid. UPM is ranked as the best technical university in Spain, and second overall. The university's Engineering degrees are considered to be the best in the country, and are highly rated in the rest of Europe, too.
UPM is also a leading institution when it comes to research - its Parque UPM is amongst the most important research facilities in the country. As the university's main campus is in the Ciudad Universitaria, you can expect to be surrounded by students everywhere you go, giving you a strong sense of community that you won't always get in other parts of Madrid.
To get to UPM, just get off the metro at Metropolitano station on Line 6, or catch one the buses servicing the area (132, F, C1, C2)
Photo Credit: Santiago Urueña Pascual - Wikimedia