Zagreb’s old town is split into the Lower town and the Upper town, lots of grand old buildings most of which are museums now, this was once a wealthy city. The lower town has some big parks and the Upper town had endless open air cafe’s and a church or two, markets, the parliament and many tourists including a few Korean and Japanese tour groups with their own guides. English is not as widely spoken.
After a day of wandering the Upper town you will be glad to get back to your desk at work to rest those aching knees and calf muscles, unfortunately I cannot afford that luxury.
The trams are modern and a convenient way to get around 12 kuna a ride about $2, there are also buses, no plastic you have to buy a ticket, they are available at kiosks and supermarkets everywhere. The trams of course only operate on the flat, no hills.