Washington, D.C. is home to famous buildings, memorials and museums that visitors love. But it is also home to a large and beautiful green space. There are many _ in the city. Today, we take you to the United States National Arboretum, an active center for both scientific research and public education. Many people who come to Washington are astonished when they first visit the National Arboretum. The Arboretum is only a short drive from the center of the city. However, visitors often feel like they are remote from the busy American capital. The Arboretum covers one hundred eighty hectares of green space in the northeast part of Washington.  The area is famous for its beautiful flowers, tall trees and other plants. About nine thousand different kinds of plants grow there. The National Arboretum was established by an act of Congress in 1927. Today, the United States Department of Agriculture's Agricultural Research Service operates the Arboretum. The goal of the Arboretum is to carry out studies and provide education in an effort to improve the environment. The goal includes protecting trees, flowers and other plants and showing them to the public. The National Arboretum is a popular stop for visitors to Washington. It is open every day of the year except December twenty-fifth, the Christmas holiday. Money is not necessary to visit the Arboretum. As many as six hundred thousand people visit the Arboretum's grounds each year. Hundreds of thousands of people also visit with the help of computers. They use the Arboretum's Internet web site to learn about current research programmes and how to care for plants. Director Thomas Elias says Arboretum officials would like to see even more visitors. He says they believe that many people do not know it exists. Part of the problem might result from the fact that the Arboretum is about five kilometers from the closest train station. Many famous places in Washington are a short walk from Metrorail, the local train system. The Arboretum is easy to reach by automobile or bus, however. About fifteen kilometers of roads have been built on the property. The roads connect to major collections and seasonal flowers. The Arboretum also welcomes people on bicycles. Disabled persons or those who want to walk only short distances may visit four beautiful areas that are close to each other. Why was the National Arboretum established by an act of Congress?
To protect and study about nine thousand different kinds of plants there. To make it a popular stop for visitors to Washington. To grow trees for Christmas. To improve the environment.