Cat Ba is the largest island in the Bay and approximately half of its area is covered by a National Park, which is home to the highly endangered Cat Ba langur. This golden-headed langur is rarely seen, as fewer than 100 specimens are thought to survive in the wild, although it is the subject of a well-organised conservation programme. The Park covers both land and marine areas and has a high biodiversity, although it is at risk from too rapid an increase in tourism. Other mammals in the Park include civet cats and oriental giant squirrels.
Outside of Cat Ba town is a beautiful island with much to explore.
The vast majority of people take a pre-booked tour from Hanoi on a tourist boat, though this is probably the slowest, least flexible and a relatively expensive way to visit Cat Ba and should be avoided at all costs unless you specifically want to be locked on a tourist boat for five hours while being given the hard sell and overcharged for the most minimal of refreshments.
It's cheaper and more flexible to come either on a non tourist boat at Halong City or via Haiphong. If coming from Hanoi, you can also take a direct, combined bus/boat trip from Luong Yen Bus Station at 5:20, 7:20, 11:20 and 13:20 which takes 4.5 hours (compare: 5 hours for a slow tourist boat just to get from Halong City to Cat Ba's northern port!) and costs 190,000 - 220,000 VND (US$9-$11) depending on season.
From Haiphong: there is a speed boat doing the trip several time a day (the last one around 16:00) from Phà Binh harbor. It costs 150,000 VND (May, 2012). Not more! The price is written on the ticket but some people sell false tickets with written 180,000 and they say the price was 150,000 last year or last month! If the boat arrive in Phù Long, they can also say that 180,000 include the bus from Phù Long to Cat Ba... but it's also included in the 150,000 VND ticket: boat and bus can't be divided... it's the same company.
There are half a dozen places to rent bikes including tandems. A ride to the other side of the island for a view into Ha Long bay and then back along the coastal road is around 45km. It's worth getting a bike with gears as there are a few hills.
National Park, Eastern part of the island (Enter eastward on the main north/south road). The domain of the endangered Cat Ba Langur, of which there are supposed to be only around 100 left. Things on offer include a walk to a peak viewing tower (1.5-2 hours round trip; slippery and muddy if it's rained recently), a frog pond (probably better in the off (wet) season), a short nature walk near the frog pond, more stuff which you can probably find online...15,000VND entry, various guided tours. edit
Caves. There are a lot of caves around the island, though none of them are particularly impressive. Some cost money and may have optional guides. You can find them using the map or signs on the island. You have to walk through some forest to some of them.edit
Beaches, Southwest side of the island (Accessible from the road). Don't expect surfable waves, though!Free. edit
Monkey Island. Several boats run day trips to nearby monkey island either in isolation or as part of a larger tour. The island apparently has monkeys, but only a few around the accomodation were in evidence. Be aware that these animals are used to getting their food from either the guests or the bins, and therefore are not afraid of humans, so they might cause a problem. There is some accomodation on the island, that is Monkey Island Resort which consists of eight small bungalows and 20 spacious deluxe bungalows, but cosy, bamboo huts just behind a secluded beach. The food was nice, the drinks cheap, and the scenery was spectacular. There's some kayaking available, and a trail for hiking to the top of the mountain where you can take so beautiful picture of Lan Ha bay. Nearby is the public beach, destination of lot Cat Ba island trips. It is probably the most beautiful junkyard in region. You can see monkeys searching food in enourmous quantity of garbage, nobody takes care. Better to avoid to visit.approx US$40 per night. edit
Ha Long Bay, Bai Tu Long Bay, (Mr. Lu inside Post Office). Organise 2 or 3 day trips into Ha Long and Bai Tu Long Bay for kayaking, caving, swimming and diving. Book via the honest and fair Mr. Lu at the post office. Prices ~$45 per person for 2 day / 1 night trip (assuming 4 people in group). Cook Bien spoke basic english and cooked delicious food, Captain Phi friendly and offered us rice wine, and night spent in quiet part of bay was magic. edit
Hospital Cave, (Off Ha Sen Road, 10km from town). A 17 room underground hospital and hideout which was in use until 1975. It's a real life James Bond underground lair. Get tickets from the café on opposite side of road.15,000. (20.7698,107.0204)edit
Cannon Fort, (2km north of town). Built in 1942 as a naval defence. Incredible views of Lan Ha Bay.50,000. (20.7233,107.0546)edit
Foot massage. Enjoy a half hour foot massage. There are several places that offer this service along Cat Ba town waterfront.US$3. edit
Take a walk around the market at the northwestern edge of town. The seafood section should give you a reasonable idea of the less exotic, locally consumed varieties of seafood caught locally.
Rock Climbing if seeing the beautiful limestone karsts isn't enough for you, try scaling them. Slo Pony /Asia outdoors located on the 2nd floor of Noble House is a good place for more information. They run full and half day trips with combinations of kayaking, climbing and cruising the less touristy karsts.
Boat Tour with Jim at the Le Pont hotel. He does boat tours through the islands and some kayaking through neat coves. $25 per person if 4 or more.
Lan Ha bay, Hai Phong city (South of Halong bay). Lan Ha bay is a unique and beautiful area comprised of hundreds of islands. There are a lot of small beaches and floating villages for example Van Gia floating village, Monkey Island beach, Viet Hai fishing village, Van Boi beach.edit
The market slightly down the Haiphong-bound road to the west of town offers some sizeable sit-down places in the rear corner that are popular with locals. It also has a great selection of tropical fruits for low prices.
Noodle vendors offer fried or pho (soup-style) noodles and fried rice for low prices (typically 20-40,000 dong) along the waterfront and across the island.
Seafood restaurants either in the bay (floating) or on the land offer a variety of seafood, with clams starting at around 80,000 dong per kilo.
Green Mango on the waterfront towards the eastern edge of town has the broadest selection of international cuisine on the island, including Indian, Italian, Thai, and Vietnamese. It's not fine dining, but it approaches the mark without pushing up prices too far. A good bet if you want a break from Vietnamese food.
Mr. Zoom hotel and restaurant (Cat Ba island), 25 1/4nui ngoc street, ☎ 01649444024, . Mostly good meals, but if he offers you an enormous (2kg) round-looking crab creature thing, save your $35.edit
Phương Phương Restaurant, 232, 1/4 street, cat ba town (near Nam Dương Hotel), ☎ 01687556989. The restaurant has views of the sea, serves Vietnamese food and Europen food.Airy space, at an affordable price. Be wary of very long wait.edit
There are a number of Sea View Bar establishments, much of a muchness.
Noble House offers 2 for 1 cocktails and free pool.
The Flightless Bird is the original bar on the island, run by a New Zealander and going strong for 15 years. The drinks menu includes reasonably priced imported bottles of wine from various parts of the world as well as a straight to the point cheap drinks section. Darts upstairs.
Rose Bar, (50m up the street behind Noble House). Awesome drink menu, most cocktails 40,000. Brand new with nice atmosphere, and a really helpful, friendly young owner. Best cocktail prices in town, if you're sick of drinking beer all the time. Open until 3:00 AM, rare in Cat Ba.edit
Mr. Zoom hotel and restaurant (Cat Ba island), 25 1/4 nui ngoc street, ☎ 01649444024, . Good meals for a cheap price.edit
Phương Phương Restaurant, 232, 1/4 street, cat ba town, ☎ 01687283786. sea view, served vietnamese food and westend food.Especialy, springroll is very good.edit
There are loads of hotels along the waterfront with little to distinguish them, though a couple have elevators if you are less mobile or are traveling with elders. A few hotels have more recently sprang up down side streets away from the water, these should be cheaper. When looking at rooms, you may pay more for a water view. Free wifi is standard. Avoid anywhere that tries to "include" breakfast, which costs almost nothing and is probably of questionable quality anyway. Similarly, avoid anywhere that prices in dollars; ask for the price in dong. Decent conversion (February 2012) is 20,000 dong to a quoted dollar rate. In off season, everywhere is empty so will compete heavily on price; a huge room for two cost 125,000 ($6) on the water (February 2012).
Sunflower One Hotel, Nui Ngoc St (central, just around the corner from the waterfront), ☎ 031 3888429, . Three star hotel, many rooms have sea views. It is often used with Ha Long Bay boat tours when an overnight stay is requested on Cat Ba island. It is a quality hotel with good food. It has wifi in rooms but can be somewhat unreliable. Its sister hotel Sunflower Two, which is often used with cheaper Ha Long Bay tours, is about 1km inland on the same road, and is not as nice. edit
Song Chanh, 178 Duong 1-4, ☎ 0978366751. A great value hotel along the main strip in Cat Ba town. Very friendly staff who can also organise onward travel or tours around the island. Ask for Mr. Thuy, and go on the National Park trek with his uncle.double and twin rooms, low season $10/rm, high season $15/rm. edit
Hotel Phu Thanh, So 176 Duong 1/4, ☎ 0313696289 or 0976506999. New hotel only opened in 2009 with really nice, large, clean rooms. Has free wifi included and satellite flat screen TV. Good showers with hot water that actually have pressure. They also serve some great food in the restaurant during the busier summer months. Friendly staff and family owned and run.Rooms start at $10. edit
Ngoc Hoa Hotel and Restaurant, 211 Duong (200m to the left of the dock), ☎ +84 16 4944 4024, . checkout: 12. Rooms facing the Bay, close to the ferry. Free wifi. Elevator. Fridge and aircon included. Family restaurant downstairs. Tours and scooters available at good prices if you ask, but the staff is not pushy. Their restaurant serves good simple Vietnamese food, soups, noodles, rice. Strong coffee and fruit smoothies. Big beer for under a dollar.10-15$. edit
Le Pont Hotel, 62-64 Nui Ngoc St, ☎ Mr. Jim +84 (0) 928 006 879. Dormitory $3.5 per person, rooms $4.5 per person, minimum two persons (April 2012). edit
Mr. Zoom hotel and restaurant (Cat Ba island), 25 1/4 nui ngoc steet, ☎ 01649444024, . Rooms are nice, clean and cheap.edit
Monkey Island Resort (Monkey Island - Cat Ba islands), Monkey Island beach, ☎ 0316299888, . This resort is ideally located at Monkey Island beach in Lan Ha bay. It is about 10 minutes going by boat from Beo harbour in Catba town. There are 29 room included 8 standard bungalows, 6 gardenview bungalows, 6 deluxe seaview bungalows and 8 comfortable suite seaview bungalows. There are spacious restaurant, game center for playing biliard, pingpong, table football, there are internet and wifi internet too. Kayaking, hiking mountain and playing games here are free.edit
Ngoc Khanh Hotel, ngoc nui (west). Cheapest in Cat Ba! super clean, nice double rooms for as little as 100.000 dong. Big comfy beds with soft matress, nice bathroom with hot water, excellent wifi signal in the rooms, satelite tv, balcony, free pool table downstairs, cheap beers, honest and helpful staff, laundry service.5 U$D. edit
To Hanoi, the easiest way to leave Cat Ba is through a booked Bus+Boat+Bus ticket. You can find these on the main beach road by the docks. Hoang Long sells combined tickets daily for 220,000, while some other companies are slightly cheaper. Takes about 6 hours.
Leaving town, boats and buses to Haiphong (150,000 dong; almost hourly from 6AM) and Halong City are available from the square on the waterfront near the boat pier. Hotels can book tickets for you at a slight premium.
From Bến phà Tuần Châu harbor to Halong City : 150,000 VND (May, 2012).
From Ben Beo harbor to Halong City : 170,000 VND - 3hours - wonderful (May, 2012).
You can then go back to Hanoi by bus for 100,000 VND (May, 2012).