Jim, our tour guide for both the free Old Town Walking Tour in the morning and the Prague Castle Tour in the afternoon, is extremely knowledgeable and very funny. Hailing originally from sunny Florida, he speaks perfect English, and as a History major, he shared his deep knowledge of Czech history, which made the tours much more enjoyable.The tours were very well organized and punctual. For groups of 9 or more, there's an upfront charge of 10 euros per person, although if you are a group of 8 or less, the booking is free, and the cost of the tour is paid at the end based on whatever value each person places on the tour.Be aware there's a lot of walking involved, although for the Prague Castle Tour, the short trip up to the Castle from near the Charles River meeting place is done via tram for a cost 30 CZ per person, approximately $1.30 (free for anyone 65 or over). If you are short on time, definitely do the Castle Tour, a UNESCO World Heritage Site, and the world's largest cathedral. As the tour is free, the visits to the interiors, which require paid tickets, are not included. However, the exteriors and views are amazing, and the Vitus Cathedral is a sight to behold!