Railhead is one word, and means the point where all of the railway lines begin or end. There is always a town at any railhead. We rode the train all the way to the railhead.

railhead

Because that's where the railhead was.

A railhead is either a point along a completed railway route that is located within a military "theater of operations" that is used to disperse supplies where needed, OR the end of an unfinished railway line. :)

Railhead

This can also be known as a Terminus.