Then I would vote for Cambridge+Somerville (only 11.33 square miles- interconnected by the Red Line subway now with an extension of the Green Line subway coming in 2021)
Harvard is the largest employer in Cambridge
MIT is the second largest employer in Cambridge
Tufts is the largest employer in Somerville
Home also to:
Lesley University
Longy School of Music
Hult International Business School
Wellesley, Babson, Olin, Brandeis and Bentley all run shuttle buses into the area
Students attending schools across the river (in Boston) also visit.