The Manapouri Underground Power Station, at West Arm, is considered New Zealand's greatest engineering feat. It is the country's largest hydroelectric power station and is unique in that nearly all of it is built underground. The only external signs are the above-ground control building, a switchyard and two sets of transmission lines that loop across the head of the arm on their way to join the national grid. A visit to the Manapouri Underground Power Station begins with a coach trip down the 2 kilometre (1.2 miles) underground spiral tunnel to the immense machine hall. Here you will learn how the Manapouri Power Station, located deep in the heart of the mountain, harnesses the energy of rushing water to generate electricity.

• Delicious picnic lunch options (must be pre-ordered)
• Te Anau coach connections and transfers from most accommodation
• Suitable for all ages