Fiber-reinforced　polymer　(FRP)-concrete-steel　hybrid　multi-tube　concrete　column　(MTCC)　is　a　new　type　of　composite　column　and　comprises　a　number　of　steel　inner　tubes,　an　FRP　external　tube　and　concrete　fillings　for　the　space　inside　all　the　tubes.　This　paper　presents　a　series　of　experimental　tests　on　four　large-size　square　PEN　(polyethylene　naphthalate)　FRP-MTCCs,　of　which　the　PEN　fibers　were　extracted　from　recycled　plastic　bottles.　The　parameters　of　interest　include　the　FRP　thickness　and　the　steel　tube　configuration.　The　experimental　results　showed　that　the　large-size　square　MTCCs　with　PEN　FRP　exhibited　excellent　ductility　due　to　the　effective　confinement　provided　by　PEN　FRP　jacket　and　steel　tubes.　A　prediction　method　for　the　square　PEN　FRP-MTCCs　has　been　developed　in　the　present　study　to　consider　the　unique　characteristics　of　the　column　and　is　able　to　produce　reasonable　predictions　for　the　experimental　results.　This　study　serves　to　present　an　innovative　alternative　in　an　environmentally　friendly　way　that　can　replace　the　conventional　bridge　piers　in　coastal　and　salina　regions.