An obelisk is a tall, four-sided, narrow tapering monument which ends in a pyramid-like shape or pyramidion at the top.
Originally constructed by Ancient Egyptians and called tekhenu, the Greeks used the Greek term obeliskos to describe them, and this word passed into Latin and ultimately English
米国最高的方尖碑obelisk大家肯定都知道，就是Washington Monument华盛顿纪念碑啦：
