Cat Ba Island is the largest island in Halong Bay. While the vast majority of Halong Bay's island are uninhabited vertical rocks, Cat Ba actually has a few tiny fishing villages. The terrain is too rocky for agriculture and most residents earn their living from the sea. Life has always been hard here and, not surprisingly, many Cat Ba residents joined the exodus of Vietnamese boat people in the 1970s and 1980s.

Although the island lost much of its fishing fleet this way, the overseas Vietnamese have sent back large amounts of money to relatives on the island, thus financing the new hotels and restaurants that you'll see.

There is very little motorized traffic and, indeed, very few roads. Compared with the tourist carnival at Bai Chay, Cat Ba is still very laid back, despite about a ten fold increase in hotel rooms since 2006.

About half of Cat Ba Island which has a total area of 354 sq km and 90 sq km of the adjacent inshore waters were declared a national park in 1986 in order to protect the islands divers ecosystems.
These include subtropical evergreen forests on the hills, freshwater swamp forests at the base of the hills, coastal mangrove forests, small freshwater lakes and offshore coral reefs. Most of the coastline consists of rocky cliffs, but there are a few sandy beaches tucked into small coves. The main beaches in Cat Ba Island are Cai Vieng, Hong Xoai Be and Hong Xoai Lon.

There are also numerous lakes, waterfalls and grottoes in the spectacular limestone hills, the highest of which rises 331 m above sea level. The growth of the vegetation is stunted near the summits because of high winds. The largest permanent body of water on the island is Ech lake, which covers an area of three hectares. Almost all of the surface streams are seasonal; most of the Cat Ba's rainwater flows into caves, and follows underground streams to the sea, creating a shortage of fresh water during the dry season. Although parts of the interior of the island are below sea level, most of the island is between 50 and 200 m in elevation.

The waters off Cat Ba Island are home to 200 species of fish, 500 species of molluscs and 400 species of arthropods. Larger marine animals in the area include seals and three species of dolphins.

Stone tools and bones left by humans who lived between 6000 and 7000 years ago have been found at 17 sites on the islands. The most thoroughly studies site is Cat Beo Cave, discovered by French archaeologist in 1938. which is 1.5 km from Cat Ba Village.

Getting there and away to Cat Ba Island

Cat Ba Island is 40 km east of Haiphong and 20 km south of Halong City. A great innovation for getting there are 108 seat russian built hydrofoils. the air-conditioned water rockets reduce the Haiphong - Cat Hai- Cat Ba Journey to just 2 hours. Vietnamese Package Tours can arrange 2 day 1 night trip to Cat Ba Island from Hanoi.
An Alternative way to reach Cat Ba Island via the island of Cat Hai, which is closer to Haiphong. A boat depart Haiphong and makes a brief stop in Cat Hai Island, before continuing to the  port of Phu Long on Cat Ba Island.