Hundred Islands National Park

Listen first. The engine of the small outrigger boat coughs, then settles into a steady drone. Salt spray lands on your arms. Ahead, the water turns from dull green to a clear, glassy turquoise. Then the islands appear — dozens of them, rounded and green-topped, scattered across the gulf like stones dropped from a great height. Some are no bigger than a house. Some carry a thick crown of trees. And many of them seem to stand on narrow stems, as if the sea has been slowly nibbling at their feet.

You are in Hundred Islands National Park, off the coast of Alaminos City in the province of Pangasinan. This is the western edge of the Ilocos Region, on the northern Philippine island of Luzon. The islands sit in Lingayen Gulf, a broad bay that opens onto the South China Sea. The name sounds like a round number invented for tourists. In fact, the count is closer to the truth than you might expect — and it changes twice a day.

Here is the first surprise. Local counts usually put the number at 124 islands when the tide is low, and 123 when the tide is high. One small islet simply disappears under the water as the sea rises, then returns a few hours later. So the park never quite has one fixed size. If you want to be exact about how many islands you are looking at, you have to check a tide table first.

Now look closely at the rock itself. These islands are not volcanic. Geologists describe them as ancient coral, lifted above the sea over a very long span of time. Coral is made of calcium carbonate, the same mineral as limestone. When this old reef rose into the air, rain, wind and waves began to shape it. The result is pale grey stone full of holes, ridges and sharp little points. You can see it clearly where the vegetation stops and the bare rock begins.

That shaping explains the mushroom silhouettes. Waves strike the base of each island again and again. Over centuries, the water cuts a groove into the soft stone near the waterline, while the top stays wider. The islands become undercut, a bit like a cap sitting on a stem. In places, the sea has hollowed out small caves and overhangs. From the boat, these shadows look dark and cool against the bright water. It is one process, repeated across more than a hundred islands.

The Philippine government declared this area a national park in 1940, under President Manuel Quezon. That was before the Second World War reached these shores. Protection came early here, at a time when few places in the country had that status. Today the park is managed with the local city government. Most visitors arrive the same way you probably did — from Lucap Wharf on the mainland, where rows of painted boats wait at the pier.

Those boats deserve a moment of attention. They are called bangka, traditional Filipino outrigger boats. The long bamboo or wooden arms on each side, called outriggers, keep the narrow hull steady in open water. Many boatmen here come from fishing families along the Alaminos coast. They know which channels are shallow, which corners catch the wind, and where the light falls best in the afternoon. If you ask, many are happy to point out islands by name.

Only a few islands are developed for visitors. Governor's Island is known for its viewing deck at the top of a stairway. From there you can see the green humps of the archipelago spread out below you. Quezon Island, named after the president who created the park, has picnic shelters and a sandy area for swimming. Children's Island has shallow, calm water, which makes it popular with families. Most of the other islands stay wild, with no facilities at all.

Of course, people have their own stories about how the islands came to be. Locals tell several versions of a legend. In one popular tale, a giant shed tears into the gulf, and each tear became an island. In another, the islands are the remains of something ancient and enormous that sank into the sea. These are folk stories, not history. But they show how strongly the people of Pangasinan connect with this stretch of water.

Below the surface, the park is just as important. The shallow reefs around the islands support corals, reef fish and sea grasses. Over the years, scientists and local groups have worked to restore marine life here, including giant clams. These clams can grow very large and live for many decades. They filter seawater as they feed, which helps keep the reef healthy. If you snorkel, move slowly and keep your fins away from the coral. It grows far more slowly than it breaks.

The gulf also shapes daily life on the mainland. The name Pangasinan is often explained as meaning place of salt, a link to the salt-making traditions of this coast. Back at Lucap, you will see small eateries selling grilled fish, squid and the local milkfish, called bangus. Vendors sell snorkel masks, sun hats and dried seafood. The smell of charcoal smoke and sea air drifts along the waterfront, especially in the late afternoon when the boats come back.

A few practical thoughts before you go further. The sun here is strong, and the rock reflects heat. Shade on most islands is limited to a few trees and simple shelters. The coral stone is also sharp underfoot, so water shoes help a great deal. And remember that the sea controls the schedule. Calm mornings are often better for crossings, while weather in the rainy season can change quickly. Your boatman will usually know when to head back.

So take a last look around you. Notice the colour of the water directly under the boat, then far out toward the open gulf. See how each island carries its own shape — a dome, a tower, a low flat shelf. Look for the dark line of erosion at the waterline. When you leave, the islands will slowly blur into one green outline on the horizon. But the sea will keep working on them, one wave at a time, long after you have gone.