{"nrhp_refnum":"83001749","name":"IRT Broadway Line Viaduct","other_names":["Manhattan Valley Viaduct"],"category":"structure","location":{"address":"W. 122nd St. to W. 135th St., Broadway","address_restricted":false,"city":"New York","county":"Manhattan","state":"NY","lat":40.820020483000064,"lon":-73.95515083399994,"geom_source":"nps_gis"},"listed_date":"1983-09-15","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Engineering","Transportation"],"significance_levels":["local"],"summary":{"what_it_is":"An elevated subway viaduct along Broadway in Manhattan from West 122nd Street to West 135th Street, built from 1900 as part of the Interborough Rapid Transit (IRT) system. It is 2,147 feet long and has a steel arch in the center.","why_significant":"The viaduct is argued to be a significant engineering structure and a surviving part of New York's first subway system. Its double-hinged parabolic braced arch solved the problem of crossing the deep Manhattan Valley without costly realignment of the Broadway and Manhattan Street intersection. It is one of the few visible above-ground elements reflecting the engineering importance of the first subway.","narrative":"Running along Broadway from West 122nd to West 135th Street, this 2,147-foot viaduct carries IRT subway tracks over a deep depression in upper Manhattan known as Manhattan Valley. Construction of the subway began in 1900 under chief engineer William Barclay Parsons, and the system was completed in 1904. The viaduct combines three kinds of structure: granite and brick masonry approaches at each end, steel towers spanned by plate girders, and a central three-ribbed, double-hinged parabolic braced arch spanning 168½ feet over 125th Street, formerly Manhattan Street. The arch avoided supports that would have forced a costly realignment of the angled intersection of Broadway and Manhattan Street. A utilitarian steel and wood station sits above the arch. The structure remains in use and is regarded as a significant example of early twentieth-century transit engineering in New York City, and as one of few visible above-ground reminders of the first subway.","period_of_significance":"1900-04","architect_builder":"William B. Parsons, Chief Engineer","architectural_style":null,"criteria":[],"status_note":"Still in operation as part of the subway system; condition listed as excellent, with alterations to the station such as new escalators, railings and lamp posts.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:50:43.388854-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_NY/83001749.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/83001749/752c818746-800.webp","url_1600":"https://nationalhistoricalregister.com/media/83001749/752c818746-1600.webp","licence":"CC BY-SA 4.0","author":"Harrison Leong","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:125th_Street_-_Platforms.jpg\" rel=\"noopener\">Harrison Leong</a>, <a href=\"https://creativecommons.org/licenses/by-sa/4.0\" rel=\"license noopener\">CC BY-SA 4.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:125th_Street_-_Platforms.jpg"},"district":{"nrhp_refnum":"100008341","name":"West Harlem Historic District","url":"https://nationalhistoricalregister.com/districts/new-york/west-harlem-historic-district-100008341/"},"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/75319648","wikipedia":"https://en.wikipedia.org/wiki/125th_Street_station_(IRT_Broadway%E2%80%93Seventh_Avenue_Line)","wikidata":"https://www.wikidata.org/wiki/Q2188221"},"indexable":true,"url":"https://nationalhistoricalregister.com/new-york/manhattan/irt-broadway-line-viaduct-83001749/"}