This place is a true hidden gem!!!!! I will be making this trip from Aurora all the time now!!!!!

I cannot visit Denver without visiting Grandpas!! I was just in Denver for about a week and went 3 times!!! If you have never had a Grandpas burger, you should definitely have 1, or several!! I highly recommend a double meat cheese! Their onion rings are great, I always dip them in ranch!!! Try a shake while you're at it, for the full experience!!!

Amazing burgers, classic old school type of joint. Fries are super crispy and yummy. I've only had the cheeseburgers, regular size and the big size. The big one really is large! I have yet to try the chicken sandwiches or the steakburgers, so we will see! Shakes are A1

The most old school burger joint in Denver? Maybe. Nothing fancy and just like you want it from a walk up burger spot. This place has been here forever and probably will outlive most of Denver residents.

Boy was I surprised when I ate here. I assumed it wouldn't measure up to all the hype, but honestly this place is one of the best treasures in Denver. It's the epitome of a classic hole in the wall burger joint. The burgers melt in your mouth, the onion rings were addictive. I'm now obsessed! The chocolate shake and corn dogs were also superbly yummy! I can easily see how this is a local favorite. A MUST TRY.

We've passed this place for 17 years and tonight we finally stopped. Why did it take so long? Afraid of disappointment, shady federal spot, yadayada. Grandpa did NOT DISAPPOINT!!!! We got the double small cheeseburgers and omg tasty, perfect proportions and crispy edges to the patty- delightful surprising! Oh man and the onion rings- do not miss out!! At a point as we were devouring in the car- the hubs and I looked at each other and said we would totally bring Anthony Bourdain here at 1am and make sure to get the double large burger- the smalls were almost too much to Finish and the size of the large is bigger than your face!! Next to try- orange shake and chicken fried steak burger!!! We will be back.

I have this problem that I'm immediately a fanboy of any business that's...well...been in business for a long time. Grandpa's Burger Haven has been a Denver mainstay since the 1960's. It's an old school burger joint doing it their way or the highway. And who doesn't admire that? Now there are a few rules when you come here. The words "modern" or "contemporary" or "21st century" are nowhere to be found. The burgers are gigantic, roughly the size of a large donut like an apple fritter. They have regular hamburgers or steakburgers, and they're available in different sizes. From the outside looking in, you'll notice this is a burger stand not a sit down restaurant. There is ZERO seating. These burgers are meant to be enjoyed in your car like the drive thrus of yesteryear. You can try to wait until you're home to dive in, but the greasy smell of that brown bag will force you to dive in. I burnt my mouth devouring those onion rings. Man, these were delicious! Crunchy, well seasoned and piping hot. I love a good onion ring and these were damn tasty. I couldn't believe the size of the large cheeseburger. The burger and bun are the size of your face. All burgers come with mustard, lettuce, tomato, onion and pickles. You might like your burgers differently, but I, in fact, love the simplicity of these old school burger flavors. Definitely on #TeamMustard in this house. It's a behemoth to eat. It won't blow your mind, but to me it was properly cooked and dressed. I liked it! For those who love those big, big buns, Grandpa's Burger Haven has you covered. Love it or hate it, they've been in business longer than half of the population has been alive. And to me, you have to respect places that have stood the test of time.