Complex sentence: The Anglesey Coastal Path, which follows the entire way around the island, is 200 km long, takes roughly 12 days to complete, and passes by/through 20 towns/villages.
Split into simpler sentences: The Anglesey Coastal Path, which follows the entire way around the island, can be walked in full. It is 200 km long, takes roughly 12 days to complete, and passes by/through 20 Towns/Villages.