United Airlines, the airline offering the most nonstop flights from New York/Newark and  Washington, D.C., is adding daily trans-Atlantic summer-season service between Washington/Dulles and Lisbon, Portugal, May 25 through Sept. 6, 2016. www.united.com/

Lisbon, a city with 2 million people and 2500 years of history, sits on the north bank of the Tejo River, where the river meets the Atlantic. It is Portugal’s largest city and its capital, with the added distinction of being the warmest and western-most capital in Europe. Its climate is strongly influenced by the Gulf Stream. An earthquake in 1755 leveled a large portion of the city, but those areas were restored and the city retains several of its original medieval neighborhoods. Built on seven hills, some of Lisbon’s streets are too steep for cars, but visitors can and should take in panoramic views of the city by traveling to the top up elevators or funicular.