Translation:Some Czech towns lie below old castles.
History explanation. HRAD is a castle prior to about 1500. Due to nature of survival needs of that time, such castle always has walls sometimes moats and thanks to mostly hilly czech countryside nearly 100% of times on a hill, rock, above the rest of the surroundings. The higher, the better. The more difficult to get there, the better. ZÁMEK is a castle build after 1500 or later. Also translated as a castle. But more of what the French would call chateau. Might still have a moat but the later it is build the less likely a moat is. These tend to be in or close to towns and easy to access. Zámek can be "U" - by. Hrad... very unlikely.