charcoal beside the walkway to the top of khao luang mountain in ramkhamhaeng national park,

charcoal beside walkway top khao luang mountain ramkhamhaeng national park parksukhothai province thailand abstract ash asia asian background black branch burn carbon closeup coal combustion cooking dark energy environment forest fuel hardwood high holiday natural nature old pattern produce purification purity quality sidewalk stick sukhothai texture textured timber traditional travel tree trunk wood woodland