Questions & Answers about Vivo cerca; por eso voy a pie.
Why do we use cerca here instead of cerca de?
How does por eso translate to that's why?
Why is it por eso and not para eso?
We usually use en for transport. Why is it a pie?
You are right that most forms of transport take en (like en coche or en autobús). However, going on foot is an exception in Spanish. It is always translated as the fixed phrase a pie.