Hello how may I help you? I'd like some information about Prague Certainly, I can help with that. What would you like to know about Prague I am wondering what the name of the river that goes through Prague is. The Ilvava River flows through Prague Great! I thought that was what it was. Thank you! No problem! Can I answer anymore questions? Do you know how many miles long that river is by any chance? Prague is 171 miles long! How long is the river though? Sorry. I must have misunderstood your question. The IIvava is 171 miles long Awesome. Thanks for the information!