Use of zum vs. an den

In lesson 9.3 "Nach dem Weg fragen", the question asked was "Wie komme ich zum Friedrichsplatz?" The answer was "Nach ungefähr 200 Metern, kommen Sie an den Friedrichsplatz."  This is confusing from two standpoints: (1) I would have answered with a like-prepositional phrase "zum Friedrichsplatz" instead of "an den Friedrichsplatz"; and (2) the question contains the dative case whereas the answer contains the accusative case, even though both appear to involve a changing of place and both use the verb "kommen".
Can someone explain the difference? Is it that "kommen" as used in the question would be translated in English as "get to" (implying a changing of place) whereas "kommen" as used in the answer would be translated in English as "arrive at" (implying a static location)? 

Hi PaulS108,

First of all, both versions ("Nach ungefähr 200 Metern, kommen Sie an den/zum Friedrichsplatz.") are correct. 

"Nach ungefähr 200 Metern, kommen Sie an den Friedrichsplatz." - "After about two hundred meters you will get to the Friedrichsplatz."  is implying a kind of movement and therefore needs the accusative. You can think of it as "getting to a place" with the emphasis on getting there rather than arriving. 

"Nach ungefähr 200 Metern, kommen Sie zu dem/zum Friedrichsplatz." - "After about two hundred meters you will get to the Friedrichsplatz."  contains the dative case, because it's putting emphasis on the static location of the Friedrichsplatz. 

There is also a third possible answer containing the dative case:
"Nach ungefähr 200 Metern, kommen Sie an dem/am Friedrichsplatz an." - "After about two hundred meters you will arrive at the Friedrichsplatz."  Please note that this sentences contains the word "ankommen" - "arrive"  which is a seperable verb. 

I can understand that this topic can be confusing and a bit hard to grasp for a non-native speaker. I hope my answer makes sense and that it clears things up. 

Viele Grüße
Julia