Sentence:  Dr. A. V. Astin , NBS Director , opened the 5 - day session with introductory remarks , following which a total of twenty-six papers were given throughout the week by NBS scientists , from both the <WSD>Washington</WSD> and Boulder Laboratories . 
Meaning of the word marked with <WSD> tags:  the capital of the United States in the District of Columbia and a tourist mecca; George Washington commissioned Charles L'Enfant to lay out the city in 1791