Complex sentence: The town serves as the eastern gateway to the Loch Lomond and the Trossachs National Park, the first National Park in Scotland, and is often referred to as the "Gateway to the Highlands".
Split into simpler sentences: The town serves as the eastern gateway to the Loch Lomond and the Trossachs National Park, the first National Park in Scotland. Owing to its location it is often referred to as the "Gateway to the Highlands".