The 989-kilometer border between Algeria and Libya is one of the most tightly sealed and monitored frontiers in the Sahara Desert. It is a line defined by immense security concerns, separating Algeria’s deep desert from the prolonged instability in Libya. This is not a passage for travelers but a heavily fortified security zone.
There is one main official crossing point at Debdeb in Algeria, which connects to the historic oasis town of Ghadames in Libya. However, this crossing has been almost permanently closed to all but the most essential, officially sanctioned traffic for many years.
For you as a traveler, crossing this border by land is not a possibility. The Algerian government maintains a very high security posture due to the risks of cross-border militancy and smuggling emanating from the conflict in Libya. The entire border region is considered a military operational area and is off-limits.
Any plans for an overland journey between these two North African giants are not feasible. You must not attempt to approach the border region from either side. Official government advisories will state in the strongest terms that this is a high-risk area, and the border remains firmly shut to the public.