Estes Park is the gateway to Rocky Mountain National Park, but don't be in too big of a hurry to see the Park that you miss out on what I consider to be one of the crown jewels of all of Colorado.
Estes Park sits in a mountain valley, which I know is a shock given that I just said it was the gateway to Rocky Mountain National Park. It also sits next to a small lake called Estes Lake, again, I know a complete shock.
All those shocks aside the town is home to the Stanley Hotel which is where the movie, "The Shining" was filmed. The Hollywood connection notwithstanding, the Stanley is definitely worth seeing or staying at, if you can afford it and find a vacancy. It is a historic hotel with a lot of the old craftsmanship and the charm that you just can't find in more modern places. If you can't afford a stay or can't find a vacancy there, you can take a scheduled tour through the public areas of the hotel.
The Stanley was named after Freelan Oscar Stanley, who built the hotel to get to the fresh air of the Rocky Mountains due to be afflicted with Tuberculosis. Freelan was also the inventor of the Stanley Steamer, a steam powered automobile in the early days of motoring. Estes Park has a museum of Stanley Steamers that is also an interesting stop to make before going on to see the Park.
Incidentally, while we're talking about Estes Park, we should talk about the drive there. There are two main ways to get to Estes Park, one comes through the small town of Lyons and up while the other comes up through Drake Colorado. Both drives are very scenic and are both similar length (depending on which direction you are traveling), but I always preferred going through Longmont and Lyons to get to Estes Park. I just liked the scenery a little better, but I also liked to stop at a little restaurant in a very small valley right before dropping down into Estes itself. They had the best house made smoked sausages and European meals.
Be advised like many mountain resort communities that are scenic, Estes Park becomes quite crowded with traffic and tourists in the summer time. This is compounded by the many fun activities that are sponsored in the town throughout each week and weekend in the summer. Movement can be challenging by vehicle or on foot, but it still well worth the trouble. Don't miss out on this place just because of some crowds. You can minimize it by going off season or when everyone else is eating.
Speaking of eating there are many fine restaurants in Estes Park to go and try for all price ranges and tastes. Be sure to get reservations for the more popular ones, especially during the summer. Whatever you do though, treat yourself to some of the local flavors and experiences to be had in the town.
My recommendation is to base yourself at the Stanley and spend a week investigating the town and what it has to offer, along with the magnificent Rocky Mountain National Park. Believe me, there are worse ways to spend a week and ultimately you'll come back feeling like you have had a great adventure to look back on.