Darien Gap is a lethal break in the Pan-American Highway

Darien Gap is a break in the Pan-American Highway with a length of 60 miles (96 km) without roads. It makes that overland travel across Central America is pretty much impossible. This gap has been successfully crossed a handful of times -usually by expeditions equipped with off-road vehicles and staffed by special forces types, a near-impenetrable jungle that guerrilla fighters and drug runners call home.

Where is the Darien Gap?

The Darien gap is a region of southern Panama that borders Colombia and is the only overland route into South America. It consists of a large watershed, forest and mountains. It’s possible to cross it. However to all intents and purposes at the time of writing this article, and for the recent past, it is strictly off limits for the vast majority of travelers. The barrier of the gap is partly natural due the dense rainforest that covers the region and over more recent years the significant safety concerns from Guerilla activity have further reinforced this. The gap is 50km wide, stretching from the Atlantic to the Pacific. Known as a drug smuggling corridor between the two countries, it’s rarely seen by outsiders. It’s a lawless wilderness teeming with everything from deadly snakes to antigovernment guerrillas. Tens of thousands of migrants a year risk their lives to cross it.

Can you drive through the Darien Gap?

Firstly there are no roads bridging the gap between Colombia and Panama despite many efforts over the years to put one in place and you can't drive between these two countries. This means that vehicles have to be shipped. There have been various environmental and political issues in getting this commissioned and as a result there is a large untamed wilderness of around 10,000 square miles of jungle and swampland with no road infrastructure. Secondly several Colombian guerilla groups (including the left wing FARCs and right wing paramilitaries) are active in the region and therefore even if you got your hands on the most capable of 4x4 vehicles it is ill advised to attempt to cross this region. Various expeditions have crossed this area, but most of them have traveled over land and water. One of the earlier expeditions (traveling a big part of the way on a river boat) was in 1960, using Land Rover named "The Affectionate Cockroach":

Is Darien Gap Dangerous?

It’s one of the most dangerous stretches for people in the world, so crossing the Darien Gap is not advised. It is advisable if you’re looking to travel between Colombia and Panama that you seek alternative plans such as an international flight or look into the ferry services that are available. Roadbuilding through this area is expensive, and the environmental cost is high. Political consensus in favor of road construction has not emerged. Consequently there is no road connection through the Darién Gap connecting North America with South America and it is the missing link of the Pan-American Highway. Largely untouched by the modern world, it is one of the least visited places on the planet.
However whilst violent activity in the region is preventing travellers from visiting the region it is also stopping conservationists from maintaining the region and as a result small scale farmers and timber merchants are encroaching on the region to make their living from the gap’s rainforest. This in turn means the physical barrier is being slowly broken down and if the violent conflicts can be controlled (a big if as things stand) then there will be significant pressure to complete the road connection. If this does happen then there will be a requirement for significant control of the border, as it could no longer be relied on for a natural defense.
Pic: http://www.thepanamadigest.com/2010/08/again-panama-says-highway-will-not-bridge-darien-gap/