Denver is centrally located in the US which makes most flights in mainland US to Denver very affordable. While there is a ton to do in Denver, the best things Colorado has to offers lies outside of Denver. Below are the best day trips from Denver.
Estes Park

Estes Park is just over an hour and thirty minutes outside Denver. Estes Park is a great destination for groups of people that have different interests. It’s a great place to have a relaxing day shopping and eating, or for outdoor activities like horseback riding, hiking, or fishing. It’s a convenient place to visit because it’s such a small town you can park in the downtown area and explore the restaurants and shops by foot.
Colorado Springs

Colorado Springs is located just over an hour outside Denver. It’s a great day trip for anyone that’s looking to get out of the city for some beautiful scenery. Colorado Springs is most popular for Garden of the Gods which is a stunning rock formation with hiking trails around it. You can also take a scenic train to the top of Pikes Peak which is one of the tallest mountains in Colorado.
Boulder

Boulder is less than an hour drive from Denver. It’s a beautiful town nestled up against the mountains. My favorite thing to do in Boulder is shop and eat along Pearl Street. Part of Pearl Street is pedestrian only, and there are tons of unique and chain stores as well as great restaurants. I recommend Jax Fish House and Centro for a bite to eat. If the altitude is affecting you there is an oxygen bar along Pearl Street. If you want a great view of Boulder you can hike up the Royal Arch trail.
Idaho Springs

Idaho Springs is also less than an hour from Denver but really gives you the feel of being in the mountains without driving through the mountains far. It’s a hippy town with great shops and restaurants. Similar to Estes Park, you can easily walk the entire downtown area in an afternoon. Echo’s Hippie Shop is fun to browse through and The Spice & Tea Exchange has phenomenal and unique spices. Whenever my husband and I go up to the mountains we always stop at Westbound and Down Brewery for lunch.