Complex sentence: The Station biologique is situated in Roscoff on the northern coast of Brittany (France) about 60 km east of Brest and is surrounded by an exceptional variety of biotopes, most of which are accessible at low tide.
Split into simpler sentences: The Station biologique is situated in Roscoff on the northern coast of Brittany (France) about 60 km east of Brest. It's location offers access to exceptional variety of biotopes, most of which are accessible at low tide.