Stallarholmen is a locality situated in Strängnäs Municipality, Södermanland County, Sweden with 1,623 inhabitants in 2010. Stallarholmen, located on Lake Mälaren is situated partly on the mainland and partly on the island of Selaön, Sweden's largest freshwater island. The island and the mainland are connected via a bridge built in the mid 20th century. The etymology of the name Stallarholmen may be related to stables ("stall") and small islands ("holme"). An article in Strengnäs Tidning from 1927 says the word "holme" refers to the isthmus that juts out from the mainland.
https://en.wikipedia.org/wiki/Stallarholmen