Royal Australian Mint

I can't think of anywhere else with a collection of coins and other coin-related memorabilia quite like this (as you'd expect I guess!) You can just look through yourself, with explanations etc placed near important coins and that would be enough for some people. The tours give even more information, though they're not really all that kid-friendly. Interesting too to see how they make and move coins around the mint - but as Amanda noted below, it doesn't take a long time to go through.

Worth a visit, doesn't take too long to go through. Interesting to see how the blanks are turned into coins, lots of merchandise on display and commemorative coins etc to buy. Cafe is limited and it'll take under two hours to complete.