There are nearly 400 national parks in the United States. Many of them are not only spectacular, but also suitable for family vacations. In fact, visiting a national park has been our top choice for vacation trips ever since my kids were old enough to enjoy travelling. The National Park Service (NPS), in my opinion, has done a fine job maintaining the balance between tourism and preservation.

Some national parks don’t charge an entrance fee, but others do. However, every year those parks that usually charge a fee will be open for free on given days. For 2012, the fee-free days are listed below:

• January 14-16 (Martin Luther King Jr. weekend)
• April 21-29 (National Park Week)
• June 9 (Get Outdoors Day)
• September 29 (National Public Lands Day)
• November 10-12 (Veterans Day weekend)