Eureka Skydeck was great we went up just on dark, seen an amazing view of Melbourne sky turning to dark was great. The Aquarium was a great experience was set out really well, plenty of places to sit and relax while enjoying. highly recommend both.
Be sure to exchange your ticket first. With the pre-paid tickets, you can skip the long queues at both places. The Aquarium is a bit small but well worth visiting, especially the crocodile and penguin exhibit. Eureka Skydeck also boasts great view at night.
The aquarium was fabulous there was a lot more in there than I thought there would be.the sky deck was a little disappointing as the glass box off the side wasn and #39;t include. Once you were up top then I found out it was extra.