Currently because of covid restrictions entry is limited to main gate or Reeves Ave. The most direct way would be walk to your left after you enter the main gate, up the hill all the way towards Jefferson Hall. Make a right turn at Jefferson and walk the length of the quad At the end you'll see Rosenthal library. You'll know it because it has a clock tower.
QC has many entrances, the library is located almost at the center of the campus so if you reach the center you'll be able to see a building with a clock which that is the library. Each entrance also provides with a map of the campus, that'll help you better
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