Rugged, craggy and jungle-clad Cat Ba, the largest island in Halong Bay, is straight out of Jurassic Park. Lan Ha Bay, off the eastern side of the island, is especially scenic and offers numerous beaches to explore. While the vast majority of Halong Bayai??i??s islands are uninhabited vertical rocks, Cat Ba has a few fishing villages, as well as a fast-growing town.
Except for a few fertile pockets, the terrain is too rocky for serious agriculture; most residents earn their living from the sea, while others cater to the tourist trade. Life has always been hard here and many Cat Ba residents joined the exodus of Vietnamese boat people in the 1970s and ai??i??80s. Although the island lost much of its fishing fleet this way, overseas Vietnamese have sent back large amounts of money to relatives on the island, fuelling the hotel boom of the past decade. Cat Ba is still relatively laid-back, despite about a 20-fold increase in hotel rooms (and karaoke machines!) since 1996.
Almost half of Cat Ba Island (which has a total area of 354 sq km) and 90 sq km of the adjacent waters were declared a national park in 1986 to protect the islandai??i??s diverse ecoAi??systems. These include subtropical evergreen forests on the hills, freshwater swamp forests at the base of the hills, coastal mangrove forests, small freshwater lakes and coral reefs. Most of the coastline consists of rocky cliffs, but there are a few sandy beaches hidden away in small coves.
There are numerous lakes, waterfalls and grottoes in the spectacular limestone hills, the highest of which rises 331m above sea level. The largest permanent body of water on the island is Ech Lake, which covers an area of 3 hectares. Almost all of the surface streams are seasonal; most of the islandai??i??s rainwater flows into caves and follows underground streams to the sea, which creates a shortage of fresh water during the dry season.
The waters off Cat Ba Island are home to 200 species of fish, 500 species of mollusc and 400 species of arthropod. Larger marine animals in the area include seals and three species of dolphin.
Ho Chi Minh paid a visit to Cat Ba Island on 1 April 1951 and there is a large annual festival on the island to commemorate the event. A monument to Uncle Ho stands on Mountain No 1, the hillock opposite the pier in Cat Ba town.
The best weather on Cat Ba Island is from late September to November, particularly the latter, when the air and water temperature is mild and skies are mostly clear. December to February is cooler, but still pleasant. From February to April rain is common, while the summer months, from June through August, are hot and humid. This is also peak season and the island is overrun with Vietnamese tourists from Hanoi and beyond.