We will be in Sydney for a week at the end of June, traveling with teens. We are trying to decide between a day trip to the Blue Mountains or an overnight , possibly staying at Old Leura Dairy.

BeanQueen,
I would stay the night but then I am into nature of all kinds and also appreciate the cultural scene in the mountains. Don't know the Old Leura Dairy.

I also don't know the Old Leura Dairy but I would encourage you to stay overnight too. Nice to hear and see the local birds early in the morning. Plus there is a lot to do in the mountains.

Leura is IMO quite nice. I don't think you could go wrong there.

Lavandula

Another vote for an overnight in the mountains. I personally prefer Blackheath further up the mountains, Leura is just a bit twee for me.

I would also recommend Blackheath as it has the famous world heritage site 'Blue Mountains National Park' that offers lot of attractions.

Overnight for sure. There are heaps of walks and things to do.

I would stay in the Blue Mountains and do day trips to Sydney. But that is just me.

The wind eroded cave is one of my favourite spots.

Thank you for all of your replies. So much to see, too little time.

That can be said for just about anywhere.

I would certainly stay overnight... There are some great walks you could do. I have not stayed at the old Leura Dairy but Leura is a nice place to base yourself. I agree that it is a little twee but many people really like it there. I have stayed in BlackHeath in a pub for a night and it was great.

There is information and pictures of my trip here
http://www.squidoo.com/The-Blue-Mountains

If you don't have your own car consider getting a trolley bus ticket for a day and get on and off at each stop.

I agree, stay overnight.
We stayed at Bethany Manor B&B which looks to be 50yds or so from the old dairy. It's a beautiful area. A short walk across the highway bridge to Leura center.
Nice pub in Leura too.
Hope you have a car, KATOOMBA is little bit of a walk from where your staying.

Lovely place to visit, we loved it

Enjoy.