Still deciding what to do today?  Today, January 15, 2018 entrance to all U.S. national parks will be free in honor of Martin Luther King Jr.  Day.

Normally, 118 of the more than 400 U.S. national parks charge an entrance free.  However, there are a few days a year where all U.S. national parks offer free entry -including today.

The rest of the free entrance days in 2018 are listed on the National Park Service website as follows:

• January 15: Birthday of Martin Luther King Jr.
• April 21: First day of National Park Week
• September 22: National Public Lands Day
• November 11: Veterans Day

Here is the list of the national parks that are waiving the entrance fee on the dates above. The remaining U.S. National Parks offer free entry year round.

If you are planning on visiting a U.S. national park in 2018, you might want to mark these dates on your calendar.