The Rade de Brest, which covers an area of 150 square kilometres, is a self-contained cruising area in its own right and offers welcome shelter from the dangers of Ushant and the Chenal du Four. The River Aulne, in the southeast, has many pretty anchorages with steep, wooded banks. Brest Harbour is an important commercial and naval port, and does not cater for yachts. The Port du Moulin Blanc is past the commercial port to the east of the city, and benefits from the businesses around it – shops, restaurants, bars and the Océanopolis, a stunning marine conservation aquarium. It is very sheltered and is accessible in all weather.