It's not a "fictional" map like, say, Ramelle is. Mount Olympus is base on the battles around Olympus and Servia passes during April 1941:
"A ruined castle dominated the ridge across which the coastal pass led to Platamon. During the night of April 15, a German motorcycle battalion supported by a tank battalion attacked the ridge, but the Germans were repulsed by the 21st New Zealand Battalion under Colonel Macky, which suffered heavy losses in the process. Later that day a German armored regiment arrived and struck the coastal and inland flanks of the battalion, but the New Zealanders held their ground. After being reinforced during the night of the 15th-16th, the Germans managed to assemble a tank battalion, an infantry battalion, and a motor cycle battalion. The German infantry attacked the New Zealanders' left company at dawn, while the tanks attacked along the coast several hours later."