{"nrhp_refnum":"05000855","name":"Sunnybrook","other_names":["Sunnybrook Park and Ballrom","Sunnybrook Convention Center","Colonial Restaurant"],"category":"building","location":{"address":"50 Sunnybrook Rd.","address_restricted":false,"city":"Lower Pottsgrove Township","county":"Montgomery County","state":"PA","lat":40.24887883200006,"lon":-75.61047058780673,"geom_source":"nps_gis"},"listed_date":"2005-08-11","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Entertainment/Recreation"],"significance_levels":["local"],"summary":{"what_it_is":"A former dance ballroom with an attached restaurant and pub, part of the Sunnybrook picnic park complex on Sanatoga Road in Lower Pottsgrove Township, Montgomery County, Pennsylvania. The ballroom was built in 1931 and enlarged in 1937, with a 1964 restaurant and 1998 brewery/pub addition.","why_significant":"The nomination argues the ballroom is significant for its large dance floor, reported at 18,000 square feet, and its role as a regular stop for big bands of the Swing Era from the 1930s through the 1950s. It also cites the venue's broad regional draw and its place in the local entertainment history of the picnic park that preceded it.","narrative":"Built in 1931 on the grounds of Sunnybrook Picnic Park in Lower Pottsgrove Township, the ballroom was the work of Raymond C. Hartenstine, Sr., who opened it on Memorial Day after roughly eight weeks of construction. The frame building was lengthened to 176 feet in 1937, giving it an 18,000-square-foot dance floor laid in narrow maple strips. Hartenstine booked the leading big bands of the period, including Tommy Dorsey, Benny Goodman and Glenn Miller, who drew an attendance record above 7,300 in 1942. Regular radio broadcasts from the hall reached audiences across the region. The ballroom closed during the Second World War and reopened in 1945. The nomination regards its size and its long run of popular dance-band appearances as the basis for its importance in local entertainment history.","period_of_significance":"1926-1955","architect_builder":"Raymond C. Hartenstine, Sr. (builder)","architectural_style":"NO STYLE","criteria":["A"],"status_note":null,"vacant_flag":null,"machine_generated":true,"model":"claude-haiku-5-5","prompt_version":"v1.1-2026-10-29","generated_at":"2026-10-29 17:10:27.18385-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_PA/05000855.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/05000855/9c8e0738ce-800.webp","url_1600":"https://nationalhistoricalregister.com/media/05000855/9c8e0738ce-1600.webp","licence":"CC0","author":"Smallbones","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Sunnybrook.JPG\" rel=\"noopener\">Smallbones</a>, <a href=\"http://creativecommons.org/publicdomain/zero/1.0/deed.en\" rel=\"license noopener\">CC0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Sunnybrook.JPG"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71996337","wikipedia":"https://en.wikipedia.org/wiki/Sunnybrook_(Lower_Pottsgrove_Township,_Pennsylvania)","wikidata":"https://www.wikidata.org/wiki/Q16900879"},"indexable":true,"url":"https://nationalhistoricalregister.com/pennsylvania/montgomery-county/sunnybrook-05000855/"}