The now- defunct lone Legislative District of San Juan-Mandaluyong was the representation of the municipalities of San Juan and Mandaluyong in the Regular Batasang Pambansa from 1984 to 1986, and the restored House of Representatives from 1987 until 1995, when Mandaluyong was converted into a highly urbanized city and was granted its own representation in 1994.
References
Legislative district of San Juan-Mandaluyong Wikipedia(Text) CC BY-SA