Top of the 'walkie talkie' is a privately owned public space for which one needs to book a time slot online and show a photo ID walking through metal detectors on ground floor. Once you're up it feels novel. A very large roof garden covered with glass climbs up via stairs towards the North with 360 degree panaromic views of London. Structure enveloping the space is white painted steel with all the necessary hierarchies executed so cleanly that it makes it look easy ! The central restaurant bit is the most disappointing part.