Haven aan den Rijn is a marina located on the Oude Rijn in Alphen aan den Rijn, in the heart of the Dutch Green Heart region. It serves as a convenient base for exploring the classic watersport circuit of Oude Rijn – Braassem – Kaag-Leiden – Oude Rijn.

The marina offers around 70 berths in total, including fixed berths and visitor spaces, sized for boats from six to twelve meters.

Floating pontoons with finger piers, individual electrical hookups per berth, toilet and shower facilities, and a 20-ton fixed boat lift are among the on-site amenities.

A boatyard on the premises handles repairs and maintenance, and winter storage is available. The harbor's central location means boats can depart directly under the Rijnhavenbrug — with a clearance of 2. 45 meters — and onto open water.

A waterfront square with a walking promenade connects the marina to Alphen aan den Rijn's town center.