The Potomac Riverboat Company invites a group of four to take a water taxi on a round trip between Alexandria, VA and National Harbor, MD. Visit the charming historic seaport of Alexandria before heading off for the day to explore  National Harbour's 300-acre waterfront property in Prince George's County. There you will find events and activities for the whole family. including The Food & Wine Festival and Yacht Show in the Spring, Foster's Clambake in the Summer months, Octoberfest in the Fall and the Annual Tree Lighting and Holiday Market in Winter.