It's my first visit to Prague , I'll be here for three days for a conference , then I have a day on my own to do some sightseeing before I head back home . What do you suggest I see when I'm here ?   There are many interesting places you should be sure to see . One problem is transportation , however . Because the city is very old , the roads are narrow and congested . If you only have three or four days to visit , you don't want to spend them waiting in traffic in a cab . I suggest you take the subway . 