A large portion of Australian’s who live in NSW probably remember going on a school trip to Jenolan Caves at some point during primary school. I was in year 4 when my class went and we stayed the night in Caves House, the historic onsite accommodation on the isolated site of the caves. I don’t remember much of the caves themselves but I do remember being very impressed by the blue lake that greets you when you arrive at the site. I am still in awe of the unnatural colour of the water today. I took so many photos!
If you can only make it to one cave, I highly recommend the cave we visited, The Orient Cave. It is as beautiful as promised and was the tour guides favorite cave as well. The tour last about hour and a half and while this is plenty of time to enjoy the caves beauty, I didn’t want it to end. This time I know that I will remember the caves well. Unfortunately, my camera ran out of batteries right at the beginning of the tour, so my photos don’t really convey how beautiful it is. I suspect it is probably something you have to see with your own eyes for it to be truly appreciated anyway.
We also did the complimentary self guided tour of the Nettle cave and the Devil’s Coach House, which gives you a lot of interesting information about the history and formation of the caves. The Devils Coach house huge and impressive.
I recommend packing your own lunch. The food from the kiosk was very overpriced and very average. Watch out for the very cute but cheeky, rosellas that help you eat your lunch! It is also a beautiful spot to have a picnic or BBQ and there are gas powered/coin operated BBQ s on site. 
There is no public transport to the cave but Trolley Tours have a daily tour leaving from Katoomba at 9am and there are regular trains to Katoomba from Sydney. There are also day tours with various companies that leave from Sydney.
Enjoy!
The Local Sydney Tourist 