Unless you’re particularly fond of long lines you’ll want to begin looking into reserving tickets online to the Observation Deck of the Petronas Towers in Kuala Lumpur, Malaysia at least 48 hours in advance. You won’t be completely immune to queuing though as the online ticketing system only guarantees you hours long waits to see Malaysia’s capital city from above, which I opted not to, since I rarely go to the top of tall buildings when traveling for this very reason. The 80 Malaysian ringgit (~$25 USD) tickets also get you a walk on the Sky Bridge, a nightmare of an experience according to most travelers on TripAdvisor.
Though from the exterior, the Twin Towers are equally, if not more impressive as getting them into any camera angle helps you appreciate the world’s 7th tallest building(s). Once you’ve built up an appetite from photographing outside and wandering around the elegantly designed lower floors you’re better served filling up at the lunch buffet of SB Corner, about a 15 minute walk away.