Plan for about an hour, maybe more on weekends.
An hour is a safe bet. Most observation towers work the same way: get in line, buy a ticket (or scan a pass), ride the elevator, spend 15–20 minutes looking around, then ride back down. For a popular spot like Prospect Point, add wait times for the elevator and maybe a security queue. That usually lands you at 45 minutes to an hour total if it’s a normal day.
Weekends and holidays can double that — especially in peak season. If you’re visiting during a school break or summer, budget 90 minutes to be safe. If you have the option, go early right when it opens, or late in the evening when crowds thin out.
Check the live webcam before you go.
