Complex sentence: Poseidonos Avenue runs in the western part of Alimos, with the Hymettus mountain to the east meeting mainly grassland, while areas to the north of Argyroupoli are forested.
Split into simpler sentences: Poseidonos Avenue runs in the western part of Alimos. The Hymettus mountain is to the east and is mainly grassland while areas to the north of Argyroupoli are forested.