RECOMMENDED LESSONS: Runoff Runoff is precipitation that did not get (infiltrated) absorbed into the soil, or did not evaporate, and therefore made its way from the ground surface into places that water collect. Runoff causes erosion, and also carry chemicals and substances on the ground surface along to the rivers where the water ends up.
Noun. 1. obelisk-a stone pillar having a rectangular cross section tapering towards a pyramidal top. pillar, column-a vertical cylindrical structure standing alone and not supporting anything (such as a monument).
After more fits and starts, the monument was finished in 1884 and opened to the public in 1888. The tapered shaft, or obelisk, is made of stone and is covered with white marble. The monument stands just over 555 feet. Memorial stones from the 50 States, foreign countries and organizations line the inside walls.