You can go to upper town by short funicoler and spend your time here.
Stone gate and broken relationship museum and St, mark church(it is close to visit inside of church) and some other museum and gallery are in upper town.
You can walk in historical street and has a good view to Zagreb.
Plan on spending a good part of the day in the Upper Town. For an extra bit of fun...take the world's shortest funicular up to the top of the "hill."
There's upper town and lower town. Both are splendid. Each is quite different from the other. Zagreb's not a huge place. It's slightly larger than Portland, OR. You'll doubtless go to both--to both the upper and lower towns, that is. You might go to Portland, too, why not? Anyway, the upper town has the very attractive St. Mark's Church, the lovely Park Bele IV, and the Lotrščak Tower among other delights, including several spots from which to view the lower town.
Everywhere you look were amazing buildings, clean streets, beautiful churches (although many were closed to visitors). What a fun place to walk--so many streets closed to cars, so it was really peaceful. Check out the street lamps that still run on gas! Take the funicular (only 4 Kuna per ride) up for a fun experience.
In my opinion this is the most beautiful part of the town, as the houses are older and the atmosphere felt more relaxed than on the lower town (maybe because of the big amounts of tourists down there). It is worth to stroll around in here!
