Located close to the world heritage site of Ha Long Bay, Cat Ba Island is considered the pearl of Viet Nam. Cat Ba is the place where the forests blend with the sea creating incomparable sights. 

Coming to this beautiful island, visitors can not only bathe in the blue sea but also explore the mysteries of nature through the primitive forests on the island. Especially, due to situated at the end of the strategy arcs range, this island is regarded as a huge fortress day-and-night guarding the sea route that goes into the Northeast area of Viet Nam. Height 177 on Cat Ba Island became important position and very difficult of access with heavy responsibility for guarding the country's territorial waters and airspace.
 
The height 177 is also known with another name as Cannon (Than Cong) Fortress, located in the Cat Ba Tourist Area, Cat Hai District, HaiPhongCity. The Cannon Fortress, located atop the hill at 177m above the sea level, is a historical vestige including battle of huge size cannons and trench and shelter systems of fortifications that were built in 1940s.

Thanks to the favorable position where the observed point protrudes into the sea and at the height ones can see a bend of the East Sea in sight, the mountain ranges behind as a support, the Cannon Fortress has became a historical witness coming along with the Cat Ba military and civilian through two fierce wars against the French colonists and Americans, contributing to make glorious feat of arms. Two cannons, each weighing tens of tons, have preserved here as historical memorials. 
 
From the Cannon Fortress, visitors will have the opportunity to contemplate the scenic of Cat Ba Island from different angles, enjoy the beautiful nature that captivates one’s heart by islands, dreamlike beaches, place-names associated with the history and legends long time ago. Situated at the foot of the mountain are the two most beautiful beaches of Cat Ba - Cat Co 1 and Cat Co 2. Looming in the distance, bobbing on the waves is Guoc Rock, LongChauDragonEyeIsland, Hai Rock, Ban Rock, Voi Phuc (Elephant Kneeling), Cat Ong, AngThamMountains, MonkeyIsland... At this altitude, the Bay of Cat Ba appears lively and crowded with hundreds of moored fishing boats and floating houses on the sea.
 
Especially, when sunset, the sun as a blazing red coal appear and disappear alternately in the mountains, visitors will enjoy the romantic and quiet space of decline of day on the sea. Visitors will be truly overwhelmed by perfect contours that the creator and the natural have painted on the blue sea background, creating an unrivaled picture.
 
The Cannon Fortress has been officially opened to visitors since June 13, 2010. Nowadays, coming to Cat Ba, visitors have one more meaningful choice to get nearer the nature - where the heaven in harmony with the earth - and the good historical values of the nation.