Consider doing the "Whanganui River & Road Combo", which includes riding with the Mail Bus up the Whanganui River Road to Pipiriki, then taking a jetboat up the River to access the Bridge to Nowhere. It makes for an extremely interesting day, definitely a highlight of our time in NZ.
See either: www.whanganuiriveradventures.co.nz OR
The "Bridge to Nowhere" is a graceful concrete structure, built by four men, virtually by hand in 1935-36, at a time the NZ government envisioned the remote area along the Whanganui River in the central North Island as a place to settle returning WWI soldiers and their families. However, the Depression, falling commodity prices, flooding, erosion, and the difficult, unforgiving terrain, led to abandonment of all settlement in the area by 1942. Now the Bridge stands isolated in Whanganui National Park in the midst of regenerating wilderness. The connecting roads were never built and the only way to access the Bridge (except for multi-day overland treks) is via the River to the Mangapurua Landing. The easiest access is via jetboat from Pipiriki, followed by a relatively easy walk to the Bridge.
The Wanganui River Road from Wanganui to Pipiriki is also definitely worth seeing, but considering the narrow, winding road, plagued by slips, and the final section of loose gravel, the driver is unlikely to enjoy the trip very much. We much preferred traveling with Noel, the friendly and informative mailman, who picked us up at our motel at 7:15am. He gave an interesting commentary about the past and present of the river settlements, as he delivered mail along the road, chatted with residents, and served us morning tea at the site of the historic Jerusalem/Hiruharama convent. The old convent and the beautifully restored church, with its Maori-influenced decoration, were very interesting. Noel delivered us to the Whanganui River Adventures office at Pipiriki around 10:15, and was waiting when we returned from our river trip, for the ride back to Wanganui.
The jetboat ride from Pipiriki with Whanganui River Adventures was interesting and exhilarating. The scenery through the Whanganui River gorge is spectacular. Ken, our driver/guide, stopped a number of times to point out interesting places and artifacts along the river, which until the early 1950s was a major highway for commerce and tourism into the heart of the central North Island. After coming ashore at the Mangapurua Landing, we walked an easy 40 minutes on a well kept path and across a suspension bridge. We stopped for lunch and tea at the Bridge to Nowhere before heading back. Ken, who grew up along the River, provided an interesting commentary complete with old photos about the construction of the bridge and the rise and fall of settlement in the area. To top off the day, he treated us to a couple of spins in the jetboat on the ride back. Around 3pm we arrived back in Pipiriki, where Noel was waiting to drive us back to Wanganui.
It was a full day and one of the best things we've done so far in New Zealand. The River & Road Combo ($160 pp) is a most pleasant and relaxing way to see it all.