Complex sentence: Nafpaktia is one of the most popular mountainous areas in Greece for its scenery, and the availability of outdoor activities such as trekking, biking, horseback-riding, and archery.
Split into simpler sentences: Nafpaktia is one of the most popular mountainous areas in Greece. Visitors observe the scenery, as well as participate in outdoor activities such as mountainous trekking, biking, horseback-riding, and archery.