Free burgers at White Castle for National Slider Day

(Photo credit: White Castle)

You may want to slide into a White Castle Wednesday, May 15 for National Slider Day.

White Castle, the oldest burger chain in America, is giving away one free hamburger and a free coke at restaurants across the country.

In order to receive the free items, you have to print a coupon off their website.

Also, if you dress up like a cowboy, you'll get two free barbecue sliders.