Contrast to Dai Lai Lake, which was built for agricultural purposes, the Vac swamp is a gift that nature has bestowed on Vinh Phuc. The Vac swamp spreads across Dong Cuong communes - Yen Lac district, Quoc Luu commune, Tam Duong town. As a natural lagoon that has existed for thousands of years, it has now been put into operation and has become a favorite destination for many tourists. The reason why this place is called the Vac swamp because it used to be the home of many birds: storks, Vacs, le le, pelicans, teals... but most of them are Vacs. Therefore, the name the Vac swamp was born and exists until now. The land is good for birds to perch, and perhaps thanks to that, the Vac swamp destination has created a unique feature that nowhere has.

In addition, the Vac swamp also has a large amount of freshwater seafood such as shrimp, crab, snail, frog... The swamp plays an important role in supplying water to the city and distributing mud to the pottery village, so it has long been existed in close relationship with Vinh Yen city for a long time. The swamp is likened to a giant octopus that crept around every corner of the city. With an area of up to 500ha and many branches, the Vac swamp includes branches wriggling into each hamlet, ward and commune of the city has a total water surface area of up to 48.4km2; The lake has a deep bottom, the deepest place is about 4.5m, the circumference is estimated up to 14km. The Vac swamp also plays a role in regulating the climate, providing water for domestic use, irrigating crops in the region, and at the same time is one of the prominent places, attracting tourists of the province.

At present, the Vac swamp tourist area is one of the potential tourist destinations that Vinh Phuc province focuses on investing in building infrastructure including an entertainment complex such as a golf course, a system of restaurants, and guests. Hotels, resorts... The Vac swamp has a harmonious combination between modern construction projects and poetic natural scenery, plus extremely good services with low cost of use and close to the capital, it is very suitable for short excursions for the purpose of relaxation after a stressful and tiring working period.