만리장성 railway 촬영 식물 monochrome geological_phenomenon transport 흑백 Thoroughfare 선로 지질_현상 track greatwall photography tree 나무 plant black-and-white

Great wall

Can you see up there? I climbed up all the stairs. Easy to step forward but much harder to go backward down. So steep. The first day in Tsinghua and Insead graduate school. Happy Thanksgiving!