Hiking to the castle
You may drive up to the castle or take one of the small buses,leaving at the old townhall or you may take a walk uphill on your own.
There are several small hicking-paths leading up the hill and within 20-30 minutes you will be at the castle, depending which path you take.
Along the way you will have plenty of great views on the city, and maybe you drive up by bus and take the walk down, like I did myself. No special hiking shoes are required, but walking in high heels is certainly not a good idea.
Especially in autumn the path might be slippery at some places.
Let's face it, the "Three River Corner" is one of the highlights about coming to Passau - it is fascinating to see three rivers merge into one, forming Europe's most fascinating big river, the Danube. There are many ways to see the rivers meet, one is to take the boat trip I recommended under "General tips" and another is to get up one of the hills for a birdseye view. Finally, one is to go and stand at the Dreiflusseck itself, the tip of the Old Town, and see the Danube and the Inn flow past you. The latter option is particularly good if you travel with children as there is a good playground there. :) You can see more of the corner from the river in my travelogue.
Statue of Emenez Meier
I saw my fellow VT'ers write up of this and went to find it---just to add that it is down right on the water on kind of a lower street...a great shot for photo buffs where there also ducks and other birds around.
The pilgrimage-church Mariahilf
The pilgrimage church Mariahilf is on the right bank of the river Inn and you may see it already from far away, with plenty of steps going up the hill.
This pilgrim-church dates back to the year 1627 and it finally became the status of a special church for the fact that the austrian emperor Leopold I found shelter in Passau, while Vienna was besieged by the Turques.
In 1683 the emperor could return to Vienna and the miracle-working image of Mariahilf became famous for the help given to the Habsburg-family.
Welcome to PASSAU
Passau is situated on the confluence of the Danube, Inn and Ilz rivers near the Austrian border and therefore it is called “Dreiflüssestadt” (Three Rivers Town). Passau has about 50,000 inhabitants, quite a lot of them are students. The town attracts with its beautiful Cathedral of St. Stephan. Best way to discover Passau is by ship or on foot. Passau is affected by annual flooding, mostly in spring but its citizens have learnt to life with the flooding.