Valhalla, also known as Rosedale, is a historic home located at Poolesville, Montgomery County, Maryland, United States. It is a two-story house constructed of local Seneca sandstone, to which are attached a c. 1835 1 1⁄2-story log structure, and two small 20th-century one-story frame wings.Valhalla was listed on the National Register of Historic Places in 1982.