▁pass ▁through ▁the ▁woods ▁exposed ▁themselves ▁to ▁mal aria ▁and ▁other ▁ill ness es . ▁By ▁the ▁mid - 1 9 th ▁century , ▁when ▁the ▁clear ing ▁of ▁the ▁area ▁began , ▁Vice ▁King ▁( U par aja ) ▁P ink la o ▁changed ▁the ▁name ▁of ▁the ▁forest ▁from ▁D ong ▁Ph aya ▁F ai ▁to ▁D ong ▁Ph aya ▁Y en ▁to ▁imply ▁that ▁" the ▁wild ▁forest ▁had ▁been ▁t amed ". ▁ ▁By ▁ 1 8 8 7 ▁the ▁S iam ese ▁government ▁decided ▁to ▁build ▁a ▁railway ▁line ▁from ▁Bang k ok ▁to ▁Kor at ▁through ▁Ay ut th aya ▁and ▁commission ed ▁British ▁Railway ▁contract ors ▁to ▁make ▁a ▁survey . ▁The ▁first ▁section ▁of ▁what ▁is ▁now ▁the ▁N ort he astern ▁Line , ▁the ▁railway ▁line ▁to ▁Kor at ▁across ▁the ▁mountains ▁opened ▁in ▁ 1 9 0 0 . ▁Much ▁of ▁the ▁original ▁forest ▁cover ▁of ▁the ▁mountains ▁was ▁destroyed ▁since ▁the ▁beginning ▁of ▁ 2 0 th ▁century . ▁Following ▁the ▁completion ▁of ▁the ▁line ▁settlement s ▁were ▁built ▁in ▁the ▁area ▁and ▁trees ▁were ▁cut ▁and ▁land ▁converted ▁to ▁agricult ural ▁use . ▁ ▁Until ▁quite ▁recently ▁only ▁the ▁rail road ▁from ▁Bang k ok ▁to ▁N akh on ▁R atch as ima ▁and ▁one ▁highway ▁crossed ▁the ▁system . ▁De for est ation ▁increased ▁as ▁the ▁building ▁of ▁more ▁roads ▁connecting ▁central ▁Th ailand ▁and ▁Is an ▁began ▁in ▁earnest . ▁Th ailand ▁Route ▁ 2 , ▁also ▁known ▁as