Homo erectus was the first early human to travel outside the Africa. The proof of it is that it's fossils is discovered in different parts of world including Germany, Hungry, China, Algeria, and Java. Early human before Homo erectus is not discovered outside of Africa.
Homo erectus had all the characters developed to locomote. It had erect posture with erect legs. It can walk erectly with its long legs but a slightly bending body posture during movement.
Two fossil of Homo erectus were discovered from Java (an island of Indonesia) and Peking and were named Java man and Peking man respectively. Java man was discovered by Eugene Dubois in 1891 while Peking man was discovered by W.C. Pei in 1924 from the stone cave of Choukoutien near Peking.