One Liberty Observation Deck Philadelphia Lightning Pass. Get fast access to One Liberty's Observation Deck with the Lightning Pass. Enter the special priority access line to avoid the crowds and go straight to the top in the state-of-the-art elevator. At the top of the 833-foot (253-meter) tower, get sweeping views over the City of Brotherly Love's downtown. Enjoy aerial photo ops of sites like University City, City Hall and Love Park. Learn about Philly's history and culture from the digital touch screen displays placed around the deck's perimeter. Book and Save 9%: One Liberty Observation Deck Philadelphia Lightning Pass.