Catalina has some nice hills. Went there for 4 days with my family and rode every day (even talked my son into riding with me once). Three hills that I enjoyed:

1) Wrigley Rd. up past the old Wrigley mansion. Great views nice turns
2) Whitley Ave. near the casino and downtown has very new smooth pavement. Nice and steep, a little narrow but lots of fun.
3) Marilla Ave right next to Whitley has new pavement but not as steep.