Petal said:
but let me tell you, Bratislava is not pretty, there's not much to see and the boat trip may be nice
I think you're being a bit unfair Petal. Bratislava old town is very pretty and great for a day trip, even though it doesn't have the grandeur of Vienna.
Things we did in Salzburg
1 Guided tour of the Fortress (excellent and give yourself about 2 hours)
2 Walking tour of the Old Town ( very good, 1 hour, can be booked in the main square. Watch 'The Sound of Music' before you go and you'll recognise some of the places.
3 Have a picnic in the Mirabell gardens
4 Have a few scoops in the square beside the Cathedral as Mrs Roy max's out your credit card. Check out the painted egg shop close by. But don't break any or the owner will give you a nasty look.
5 Don't usually like Irish pubs but had good craic in The Shamrock ( i think thats what it was called)
6 Hire a car and drive to Berchtesgaden (eerie town just over the border that used to be home to the top Nazi's). Hitlers retreat (Eagles Nest) is close by but you need to take a bus up to it. Amazing views of the Alps around here.
7 Eat loads of apple strudel.
8 We went to a big underground salt mine outside Salzburg (where the town gets it's name). A real curiosity. You get dressed in a boiler suit and slide down slides, get a spin on a train and take a barge across an underground lake. You also cross the border underground. It was all a bit tacky but very enjoyable.
9 Salzburg is a great base for adventure sports - rafting, canoeing, canyoning to name a few. All can be booked at the main square.
10 We stayed in a lovely little hotel called the Hotel Hohenstraffen about 15 minutes walk from the old town. The owners had perfect English and had been to Ireland many times.They were happy to give us tips on what to do. I think it was about €100 a night.