There is no geographical feature that forms the border between Portugal and Spain. The Strait of Gibraltar and Mediterranean Sea separates Iberian Spain and Morocco. The Pyrenees Mountains forms the border between Spain and France and Spain and Andorra.
Spain is the only country to border Portugal to the east.
The Mekong River
The Great Smoky Mountains form the eastern border with North Carolina.
mostly the ozark mountains and there is many caves in Arkansas because native Americans used them for shelter in snow& rain. there are also lakes like baltz greers ferry norfolk. and rivers current foushe black seven point spring.
The Uruguay River forms the western border of Uraguay with Argentina.
The Ural Mountains
A physical feature that forms part of the border of New York State is Lake Ontario. If you mean the border around New York City, a physical feature would be the Hudson River.
Mississippi river
The Ural Mountains
Spain's borders are made up of France and Portugal. The capital of Spain Madrid. France border's Spain along it's northeast border.
France - although Andorra lies along that border - between Spain and France - nearly all of the border is with France.
The Mississippi River forms Arkansas' eastern border.
The Ural Mountains
France is on the northeastern Spanish border.
Colorado River
The physical feature that forms Uruguay's western boundary with Argentina is the Uruguay River. It also forms part of the Brazilian-Argentine border.
Spain is the only country to border Portugal to the east.