Which is the biggest college of university Cambridge?

There's no single answer to what the "biggest" college of Cambridge University is, as "biggest" can refer to several different metrics:

* Student population: This fluctuates slightly year to year, but generally, Trinity College has the largest undergraduate and graduate student body.

* Land area: This is likely Christ's College, though precise measurements and rankings aren't readily available publicly and may vary depending on how land is calculated (e.g., including gardens, etc.).

Therefore, while Trinity College is usually considered the largest by student numbers, determining the largest by land area would require more detailed and potentially unavailable information.