Penon de Velez de la Gomera, Spain, is the shortest border in the world. The military constantly monitors the 85-metre-long border to ensure security between the two countries.
San Marino is a landlocked but independent country within Italy. It is the fifth-smallest country in the world. The international borders between the two are the regions of Emilia Romagna and Marche.
A triangular picnic table lies on the international borders of Austria, Slovakia, and Hungary.
Nepal and China share one of the highest international borders in the world. A scenic route named Friendship Highway connects the China-Nepal border to Lhasa, the capital of Tibet.
Lesotho is a country surrounded by South Africa. There are eleven functional road borders between Lesotho and South Africa.
Haskell Free Library and Opera lies exactly on the international border of the US State of Vermont and the Province of Quebec, Canada.
One can cross the border from Spain to Portugal by a zipline called Limitezero in Sanlúcar de Guadiana, Spain. However, you can only do this from Spain to Portugal and not the other way around.
The DMZ (demilitarized zone) international border between North Korea and South Korea is one of the most dangerous borders in the world.
Netherlands & Belgium share one of the most confusing borders of all time. However, it's also one of the friendliest borders. One can step over the marked lines both ways as many times as you want, and nobody will ask for papers.