Summer is fast approaching, calendars are quickly filling up, and you may be planning your summer bucket list. There are SO many fantastic things going on in and around the city all of the time, it's often hard to choose what to do. Hopefully these 16 unforgettable Mile High experiences will give you a kick start to planning your summer adventures!

1. See a Film on the Rocks.

It goes without saying that there's no better place to see live music than at Red Rocks' Summer Concert Series, but have you rocked a flick at the Rocks? They'll host nine films throughout the summer, each preceded by local live entertainment. Bring a blanket, a snack, and your loved ones and snuggle up for a Denver "drive-in" like no other!

2. ArtStir & Denver Day of Rock

Check out ArtStir, a showcase of 100% Colorado artists in the fabulous open-air Denver Pavilion in the heart of downtown. It's a great way to kick off the summer! On Memorial Day weekend, over 100 local and regional artists and craftsman of all sorts will have paintings, sculptures, photographs, textiles, and more for your viewing (and purchasing) pleasure. The event coincides with the Denver Day of Rock at 16th Street Mall, a free one-day family-friendly live music festival that unites the community and raises funds and awareness for local non-profits. Do it, Denverites!

3. Make a run for it at the Colfax Marathon!

You don't have to be a seasoned marathon runner to participate in the Colfax Marathon. (In fact, you don't even have to run at all). Choose from any of the 7 races in 2 days, including routes that take you through the Denver Zoo and Mile High Stadium. Or simply motivate runners from the sidelines and give out plenty of high fives afterwards at the celebration in City Park. (But I suggest you grab your guts and gusto and experience the city in a truly unforgettable way)!

4. Buy something legendary at Rockmount Ranch Wear.

If you're looking for timeless Western wear, look no further! This third-generation Denver icon has been providing us with authentic snap shirts, bolo ties, and the like for half a century. Every Denverite should don some Rockmount!

5. See the Rockies by horseback!

Now that you've got your authentic pearl-snap shirt, you should probably take it out for a spin, and I can't think of a better way than by seeing the Rockies on horseback. There are plenty of great stables near Denver to choose from, including 12 Mile Stables, Chatfield Stables, Bear Creek Stables, A&A Historical Trails, and more. Giddy up!

6. Be a river rat for a day.

There are tons of rafting companies outside of the city offering whitewater adventures on the Colorado River, the Arkansas River, and Clear Creek. Whether you're looking for Class 5 rapids or more of a family-friendly outing, your river escapades await!

7. Eat the notorious Rocky Mountain Oysters.

One of Colorado's rites of passage is most definitely eating Rocky Mountain Oysters, which are in fact not oysters at all, but rather a novelty (delicacy even) of bull, pig, or sheep testicles. (Yes, you heard me: Testicles). Grow a pair and go out and get some cowboy caviar!

8. Try ALL the green chile in town...

...until you find the best around (if there is such a thing).

9. Pitch it! Is there anything better than sleeping under the Rocky Mountain stars?

10. Perhaps waking up to a double rainbow?

Whether you go car camping, glamping, or retreating into the backcountry, just get out there and pitch it!

11. Feast your eyes on a summit sunrise.

Pick your favorite local hike or maybe a nearby 14er, rise before dawn, and hoof your way to the summit for sunrise. Trust me, it's a feeling you'll NEVER forget!

12. See a sunrise over Sloan's Lake from Lakeview Lounge.

Lakeview Lounge has an unofficial sunrise service on daylight savings, but who says you have to limit it to that? You can see a glorious Mile High sunrise from one of the city's most divey dive bars any day of the week. They're a dog friendly, cash only, NO frills, slightly stinky establishment open daily at 7am.

13. Go on a full moon hike.

One undeniably memorable Mile High activity is to plan and execute a full moon hike. Make sure to map your routes and bring proper gear and sustenance...but most of all, grab a gang of friends and embark on a sure fire Colorado adventure!

14. Get decked out and go on a Denver Cruiser Ride.

One of the most notable summertime traditions in Denver is the weekly Wednesday night Cruiser Ride around downtown that runs mid-May to September. This mobile costume party has a designated theme each week, and pedalers are encouraged to go ALL out, so don't be shy! (Themes this season include Prom, Animal House, and my personal favorite, Bubble Wrap, Duct Tape, and Cardboard). Oh, the possibilities!

15. See ALL the summer concerts!

No matter where you turn in the Mile High City this summer, there's an amazing outdoor concert series just waiting to be heard. There are some for a fee and others for free, so check local listings for series at the Denver Botanic Gardens, Fiddler's Green, Red Rocks, City Park Jazz, Coohills Beats on the Creek, the Clyfford Still Museum lawn, and more.

16. Go skiing at A-Basin.

Sure the activity at most of Colorado's ski resorts comes to a screeching halt in April, but did you know A-Basin is open till at least June!? (And I've heard whispers of earning turns as late as 4th of July). The snow goes on forever, and the powder never ends!

What did we miss!? Share your summer bucket list in the comments below.