We went there after having lunch at the Food Court on the 4th floor of the Petronas Twin Towers. Bought tickets at the counter, which was quite cheap RM15.00 for Adults and RM5 for children aged 3-12 years old. Disclosure:

My Hotel Review of Impiana KLCC
Impiana KLCC is a great home base for exploring Kuala Lumpur I chose the Impiana due to its location as we were planning on visiting the Aquaria and Petrosains. Disclosure: This page contains affiliate links, and at no additional cost