WALLS WORK THESE COUNTRIES BELIEVE THEY DO

2015:Estonia is to build a fence along its eastern border with Russia
(AFP Photo/Csaba Segesvari

Estonia–Russia border fence
India-Bangladesh
Chinese–Korean border fence

Egypt–Gaza barrier

Finland: About 450 miles of barbed wire fencing prevent reindeer from wandering across the border into Russia.
 France: The mile-long wall at Calais was funded by the United Kingdom to prevent migrants from accessing the Channel Tunnel that connects Britain to continental Europe.
 Morocco: A 1,700-mile sand wall fortified and surrounded by millions of land mines was built by Morocco in 1975 along disputed, ungoverned territory on its border with Western Sahara. 

Spain: More than two decades ago, the Spanish government built 20-foot concrete barriers to wall off Melilla and Ceuta, Spanish-administered enclaves in Morocco since the 15th century, to increase border security against African migrants.
Saudi Arabia: In 2014, Saudi Arabia built a 550-mile-long wall with Iraq, a response to the rise of the Islamic State militants sweeping across parts of that country.
Turkey:  A buffer zone splits the island of Cyprus and its capital Nicosia between Turkey and Greece. Nicosia is arguably the last city in the world physically separated by a wall.

Ecuador

In 2017, Ecuador began building a border wall along its 1,529 km (950 mile) border with Peru in order to stop smuggling.^[11][12] Peru subsequently asked that Ecuador immediately stop construction

List of current Countries with barriers