Complex sentence: It is located 15 km north of Madrid and has an extension of over 2,200,000 m², of which nearly 770,000 are urbanised and about a third of them garden areas.
Split into simpler sentences: It is located 15 km north of Madrid and has an extension of over 2,200,000 m². Of these are nearly 770,000 urbanised and about a third of them garden areas.