In addition to the activities available in Bethlehem and Allentown, it is common for students to visit Philly or NYC. Philly is about 1 hour and 15 minutes from Lehigh. I think NYC is about 1 hour and 30 minutes.
D spent one weekend in NYC with friends last semester, and also went to Philly for a weekend. She has attended a few athletic events and is involved in clubs and activities on campus. Plus, homework occupies a fair amount of her time.