Almost forty kilometres south of Oamaru on SH1 the large, grey and almost perfectly spherical Moeraki Boulders (some of which reach 2m in diameter) lie partially submerged in the sandy beach at the tide line. Their smooth skins hide honeycomb centres, which are revealed in some of the broken specimens. The boulders once lay deep in the mudstone cliffs behind the beach, as these were eroded, out fell the smooth boulders, and their distinctive surface pattern was formed as further erosion exposed a network of veins. The boulders were originally formed around a central core of carbonate of lime crystals that attracted minerals from their surroundings – a process that started sixty million years ago, when muddy sediment containing shell and plant fragments accumulated on the sea floor. The masses formed range in size from small pellets to large round rocks, some with a small void in the middle. There were a large number of these boulders in the area, but the smaller ones have all been carted off as souvenirs over the years, leaving only those too heavy to shift.
The picturesque fishing village of MOERAKI, 1km to the south along SH1 then 1.5km down a side road, makes a tranquil place to break your journey. Apart from easy access to the boulders, there's a chance to see yellow-eyed penguins up close. Follow signs to the white wooden lighthouse (1km off SH1 then 5km down an unsealed road). Alongside the lighthouse a path leads down to a hide, overlooking the beach at Katiki Point. Here yellow-eyed penguins emerge after a hard day's fishing (3.30pm– nightfall), and there are often seals visible on beaches nearby. The second path from the lighthouse heads off to the pa site, its importance explained on a panel nearby.