Hang Câu

Hang Câu sits at the base of Núi Thới Lới on Lý Sơn's northeastern shore, in thôn Đông, An Hải commune - a stretch of beach flanked by near-vertical basalt cliff faces that drop directly into the sea. The cave and cliffs formed from the eruption of Núi Thới Lới, the island's largest volcano, roughly a million years ago, with the sea gradually eroding the base into the hollows and rock formations visible today.

The name 'Câu' is explained two ways locally: some say it comes from rau câu chân vịt, a type of edible seaweed once found covering the cliffs here (used in the dessert xu xoa); others say it refers to the rocky ledges here being ideal spots for fishing (câu cá). Either explanation ties the name to the area's natural life.

The water in front of the cliffs is clear and shallow close to shore, with coral reefs accessible without a boat, though conditions can vary - some patches of dead coral and occasional currents mean it's worth checking locally before swimming out further. Along the road up toward Núi Thới Lới, above the main beach area, a clifftop viewpoint has become a popular photo spot with young Vietnamese travellers, who shoot from a distance to capture a sense of smallness against the vast sky.

The combination of volcanic geology overhead and blue water below makes Hang Câu one of the island's strongest visual locations - much of Lý Sơn's widely circulated travel photography is shot here.

Hang Câu is on the northeastern coast of Lý Sơn, directly below Núi Thới Lới, roughly 10km from the island's centre. From the ferry port in An Vĩnh, follow the coastal road toward An Hải and Núi Thới Lới - the beach is signposted and about 15-20 minutes by motorbike. Most visitors come directly from the Thới Lới summit by riding back down the mountain road and continuing a short distance to the beach.

The beach itself is a mix of sand and volcanic rock. The cliff face rises directly from the water on the western edge of the beach. Snorkeling is accessible without a boat - wade in from the beach and the coral begins within a short distance, though it's worth checking conditions locally, since some areas have dead coral and currents can be stronger at times. Kayak rental is available near the entrance.

The area has a few small food stalls serving fresh seafood, though quality and hygiene have reportedly been inconsistent at some of them - asking about freshness and cooking before ordering is a reasonable precaution. The beach gets crowded during peak season (Jun-Aug) and on weekends.

Hang Câu and Núi Thới Lới are part of the island's northeastern cluster - pair with a morning summit climb, then spend the afternoon swimming or snorkeling at the beach. If snorkeling is the priority, also consider a half-day trip to Đảo Bé, where coral coverage and water clarity are generally considered better.