Vietnam
The second-largest art museum in Vietnam (after the Vietnam National Museum of Fine Arts in Hanoi), the Hồ Chí Minh City Museum of Fine Arts isn't that impressive. It's located in a beautiful building designed by a French architect, but the collection isn't hugely interesting.
United States | Washington, D.C.
The National Portrait Gallery's focuses on portraits of famous Americans. Its most popular attraction is presidential portrait gallery, which has an entry for every U.S. president. While it's technically an art museum the National Portrait Gallery is also a history and biographical museum—you'll learn a lot about the people whose portraits hang in the gallery and the times in which they lived.
Denmark
Denmark's National Museum is housed in an 18th century mansion and showcases exhibitions on Danish history and culture, beginning with the Stone Age and continuing through the Renaissance. The special exhibitions are often quite good as well.
Finland
Sitting grandly atop a hill in Helsinki's Katajanokka peninsula, Uspenski Cathedral is a Finnish Orthodox cathedral. The exterior is beautiful and interior is breathtaking.
Norway
Oslo's central park is a beautiful green space with a collection of 14,000 roses and the Vigeland installation, a permanent sculpture installation including smaller sculptures as well as bridges and fountains.
Norway
Art gallery and workshop selling local hand-blown glass. The artist frequently does live demonstrations and has beautiful glassware for sale.
Spain
The home to Picasso's Guernica ( a must see sight) and has a great collection of modern art.
Spain
Spain's national art museum houses one of the finest collections of European art in the world, with pieces dating to the 12th century. Truly one of the great museums of the world, the Prado should not be missed. Allow a half day - it's huge.