The missus and I are taking a vacation to Boulder CO next month. Never been. tbh the only reason we're going is that numerous friends and family have told us "Oh, you guys would love Boulder!"
...but they haven't explicitly told us why.

So, what's good to do in Boulder CO? Any must-see places or events?

We'll be in CO to do the Triple Bypass, so we'll have our bikes with us and we definitely want to check out the road riding near Boulder. Any good routes we should do, or local clubs we should hook up with? We also like other outdoor activities, so if hiking or rafting or building huts out of mud and twigs is de rigueur, give us the inside scoop please.

We're also foodies, so we'll be looking for excellent cuisine. Doesn't have to be too fancy. Does have to be on the quiet side though.

Culture? What's Boulder have to offer?

Hook us up, yo! Thanks.

If you like climbing a lot, Flagstaff Mtn is real close in and a wonderful ride. It does get up near 20% grade in a few spots, probably 12 to 13% most of the way. If you like less intensity in climbing LeftHand Canyon is real nice. There are also some roads that top out in gravel which are in between the two of these in grade.
Pearl Street Mall is fun - on Saturday/Sunday there's a contortionist, a fire eater and a lot of great street musicians (in addition to the nice shops)
Be real careful where you park if you are getting around in a car. You're best off to get places on a bike so as to avoid getting booted.

IMO it's not just Boulder but the combined benefits of Boulder and nearby towns and the county, state and National Parks/Forests. Boulder County has been preserving open space for over 30 years, and there are many options for bike rides and hikes. You can bike highway 36 out and back from Boulder to Lyons (small town about 13 miles north of Boulder) or make a loop returning on less travelled country roads east of 36, or you can continue west of Lyons to Allenspark or Estes Park. There's lots of hiking around Boulder, but my favourite hike in the area is Hall Ranch near Lyons, Nighthawk Trail (9.4 miles out and back) or extend it by continuing on to Button Rock Preserve and Sleepy Lyon Trail to Ralph Price Reservoir and have a picnic lunch with a view of the lake. There is a network of trails just west of Boulder, I like Bear Peak Trail, or you can drive up to the Wild Basin entrance to Rocky Mtn National Park. There are music festivals in Lyons in late July and August, or you go to a concert or just hike Red Rocks Amphitheatre near Morrison. For restaurants In Lyons I like Mojo Taqueria, in Boulder, Black Belly Marketplace in east Boulder, Pasta Jays on the Pearl Street Mall, Sherpas near the mall, or there are many other more expensive restaurants. There are several book stores, bike shops and coffee shops & restaurants on the Pearl Street Mall - I like the Boulder Bookstore and the Trident Cafe & Bookshop. You can check our Vecchios bike shop on Pearl just east of the mall. There is a very cool laser cut wood puzzle shop on the mall, Liberty Puzzles, expensive but very cool and worth checking out. When I first started visiting Boulder I'd stop in at the Boulder Shambhala Center on Spruce St. near the mall, they were very welcoming to a visitor who wanted to do a sitting or walking meditation. It's also just a few steps from Lucillles, my favourite breakfast place in Boulder.

It's good to become familiar with the local ambiance:

https://local.theonion.com/five-or-s...-wh-1819565638