It is incredible that my son has to commute to the neighboring town just to get a few books to read.

neighboring 是动词 neighbor（邻近）的现在分词形式作形容词使用，由 neighbor（邻居）加后缀 -ing 构成，表示"邻近的、相邻的"。这里指地理位置上相邻的城镇。